HK1035330B - Use of histamine for elevating blood histamine levels - Google Patents

Description

Use of histamine to elevate blood histamine levels

Technical Field

The present invention relates to methods of administering histamine in combination with other agents to treat tumors or infectious diseases. The other drug may be a drug which stimulates the proliferation and/or cytotoxic activity of Natural Killer (NK) cells and Cytotoxic T Lymphocytes (CTLs) in synergy with histamine. In addition, the additional agent may be a chemotherapeutic agent, an antiviral agent, a vaccine or an antibiotic. Methods of histamine combination therapy also include drugs that act synergistically with histamine to promote cytotoxicity of NK and CTLs as well as chemotherapeutic drugs.

The invention also relates to increasing the level of histamine in circulating blood of an individual having low levels of histamine in circulating blood over an extended period of time. Such low histamine levels may be caused by tumors, viruses or other infectious agents or pathological conditions.

The present invention is based on the surprising discovery that despite the short in vivo half-life of histamine previously reported, it is possible to achieve stable and beneficial levels of circulating blood histamine after the last administration of histamine and to maintain such beneficial levels for hours or days. This discovery has prompted the combination of therapeutic approaches to maintaining beneficial circulating blood histamine levels with other drug therapies. The invention also relates to improvements in methods of histamine administration. The following presents a simplified summary of the invention in order to explain the principles of the invention.

Background A. cell types associated with the generation of an immune response

Recent anti-tumor and anti-viral regimens have focused on the host immune system as a means of treating and combating tumors and viruses. The immune system involves a complex mechanism to recognize and destroy foreign cells and organisms present in the host. The use of autoimmune mechanisms to achieve effective treatment of malignant tumors and viral infections is a promising approach.

The immune response is performed by a series of effector cells each having its own characteristics and roles. One type of effector cell, a B cell, produces antibodies to foreign antigens that invade the host, which in combination with the complement system, directly destroys the cell or organism that carries the antigen of interest.

Another class of effector cells, T cells, is divided into subpopulations that perform different functions in the immune response. Cytokines secreted by T helper cells promote proliferation of other cells necessary for the development of an effective immune response, while T suppressor cells down regulate the immune response. A third subset of T cells, cytotoxic T Cells (CTLs), is capable of directly lysing those target cells on which the foreign antigen is present.

Yet another type of effector cell is the natural killer cell (NK cell), a type of lymphocyte that is capable of immediately recognizing and destroying virally infected cells and a variety of malignant tumor cells. This property of NK cells makes them attractive candidates for anticancer and antiviral therapies based on the host's own immune system as an anti-malignancy and viral weapon. B. Cytokines involved in mediating immune responses

The interactions between the various effector cells listed above are influenced by a series of chemical factor activities that promote or reduce the immune response as desired. These chemical mediators can be produced by the effector cells themselves and affect the activity of immune cells that are the same or different from the factor-producing cells.

One class of chemical mediators of the immune response are cytokines, a class of molecules that stimulate the proliferative response of cellular components of the immune system.

Interleukin-2 (IL-2) is a cytokine synthesized by T cells, and IL-2 and its role in the response of T cell proliferation (expansion) to antigens were first identified (Smith, K.A. sciences 240: 1169 (1988)). IL-2 is known to be essential for the full maturation of cytotoxic effector T Cells (CTLs), which plays an important role in host defense against viruses. Several studies have demonstrated that IL-2 has an anti-tumor effect, which makes it a promising drug for the treatment of malignant tumors (see, e.g., Lotze, M.T., et al, eds. K.A. Smith, "Interleukin 2", Academic Press, Inc., published by San Diego, CA, pp.237 (1988); Rosenberg, S., Ann.Surery 208: 121 (1988)). In fact, IL-2 has been used to treat patients with malignant melanoma, renal cell carcinoma, and acute myelogenous leukemia (Rosenbery, S.A. et al, N.England J.Med., 316: 889-.

NK cells appear to be responsible for the antitumor effect of IL-2. For example, IL-2 rapidly and efficiently increases cytotoxicity of isolated human NK cells in vitro (Dempsey, R.A. et al, J.Immunol, 129: 2504 (1982); Philips, J.H. et al J.exp.Med.170: 291 (1989)). Therefore, cytotoxicity of IL-2 treated NK cells was higher than the constitutive (constitutive) level of cytotoxicity found in untreated cells. Moreover, depletion of NK cells in animals abolishes the antitumor effect of IL-2 (Mulle, J.J., et al, J.Immunol. invest.139: 285 (1987); Lotze, M.T., et al, supra). Yet another evidence for NK cell effects stems from the discovery that NK cells are the only quiescent (suppressing) human peripheral blood lymphocytes that express IL-2 receptors on cell surfaces (Caliguri, M.A., et al, J.Clin. invest.91: 123-132 (1993)).

Another cytokine that is considered to be an anticancer and antiviral drug is interferon- α. Interferon-alpha (INF-alpha) has been used to treat leukemia, myeloma, and renal cell tumors. Isolated NK cells have increased cytotoxicity in the presence of INF- α. Thus, like IL-2, INF- α also potentiates NK cell-mediated cytotoxicity (Trinchieri, G.Adv.Immunol.47: 187-376 (1989)). C. Therapeutic results in vivo with histamine and histamine agonists

Histamine is a biogenic amine, i.e. an amino acid which after decarboxylation can be mediated by a pharmacological receptor to produce a biological activity. The role of histamine in immediate hypersensitivity has been well established (platout, M. and Lichtenstein, L.M.1982 histamine and immunoreaction, see Ganellin, C.R. and M.E. parsons, eds.: histamine receptor pharmacology John Wright & Sons publication, Bristol.392-435).

Studies on whether histamine or histamine antagonists could be used to treat tumors gave conflicting results. Several reports indicate that histamine alone inhibits tumor growth in malignant tumor-bearing hosts (Burtin, Cancer Lett.12: 195 (1981)). On the other hand, histamine has been reported to promote tumor growth in rodents (Nordlund, J.J., et al, J.invest.Dermatol.81: 28 (1983)).

Similarly, contradictory results were obtained when evaluating the action of histamine receptor antagonists. Several studies have reported that histamine receptor antagonists inhibit the growth of rodent and human tumors (Osband, M.E. et al, Lancet 1 (8221): 636 (1981)). Additional studies have reported that this treatment promotes tumor growth and may even induce tumors (Barna, B.P. et al, Oncology 40: 43 (1983)). D. Synergistic effect of histamine and IL-2

Despite the contradictory results obtained by histamine alone, recent reports clearly revealed that histamine synergistically acted with cytokines to increase cytotoxicity of NK cells and CTLs. Thus, combined treatment with histamine and cytokines represents a promising antitumor approach based on the use of the host immune system to attack malignant tumors. Similarly, it is also contemplated to employ any of the well-known antiviral drugs in antiviral therapy.

Studies with histamine antagonists have shown that histamine synergies are via H expressed on the cell surface of phagocytic cells such as monocytes, macrophages and granulocytes₂-receptor-effected. E.g. H₂The receptor agonist Dimaprit is capable of potentiating NK cell-mediated cytotoxicity, whereas structurally similar analogs lack biological activity without effect. Furthermore, H₂The receptor antagonist blocks the action of histamine and Dimaprit, indicating that H₂The receptor transduces the histamine response (Hellstrand, K. et al, J. Immunol, 137: 656 (1986)).

The synergistic effect of histamine in combination with cytokines is not due to the direct positive effect of histamine on the cytotoxicity of NK cells and CTLs. Rather, the synergy results from inhibiting other cell-mediated down-regulation of cytotoxicity in co-existence with cytotoxic cells. Some evidence provided in the discussion that follows suggests that the synergistic effect of histamine results from the inhibition of negative signals (negative signals) emitted by other cell types.

U.S. Pat. No.5348739, incorporated herein by reference, discloses the synergistic effect of histamine and interleukin-2. As previously mentioned, IL-2 generally induces a cytotoxic response in NK cells. In vitro studies with NK-cells alone demonstrated that IL-2 administration elicits cytotoxicity. However, the increase in NK cell cytotoxicity induced by IL-2 was inhibited when monocytes were present.

In the absence of monocytes, histamine did not affect or slightly inhibit NK-mediated cytotoxicity (U.S. Pat. No. 5348739; Hellstrand, K. et al, J. Immunol 137: 656(1986) Hellstrand, K. Hermodsson, S., int. Arch. allergy appl. Immunol 92: 379-one 389 (1990)). However, NK cells exposed to histamine and IL-2 in the presence of monocytes exhibited increased cytotoxicity (supra) compared to the cytotoxicity obtained by NK cells exposed to IL-2 alone in the presence of monocytes. Thus, the therapeutic result of the synergistic potentiation of NK cytotoxic effects of the combination of histamine and IL-2 is not derived from the direct action of histamine on NK cells, but rather from the inhibition of monocyte production of inhibitory signals.

Without being limited to a particular mechanism, it is believed that the inhibitory effect of monocytes on cytotoxic effector cells such as NK cells and CTLs is derived from H produced by monocytes₂O₂. H produced by monocytes₂O₂The cytotoxic effect of NK cells has been reported (Van kessel, K.P.M. et al, immunology, 58: 291-296 (1986); EI-Hag, A. and Clark, R.A. J. immunology, 133: 3291-3297 (1984); Seaman, W.E. et al, J. Clin. Res. 69: 876-888 (1982)). H₂O₂Another evidence for the cytotoxic effect of NK cells is that in vitro studies have found that addition of catalase, a scavenger of H, during preparation of monocytes and exposure of NK cells to IL-2₂O₂The enzyme of (4) can remove the inhibitory effect of monocytes (Seaman, supra). Thus, histamine may be H produced by reducing monocytes₂O₂To exert their synergistic effects (Hellstrand, K., Asea, A., Hermodsson, Histamine-regulated antibody-dependent cytotoxicity of S. granulocytes, monocytes and natural killer cells, J.Leukoc.biol.55: 392-.

Monocytes are not the only cell type that can down-regulate NK cell and CTL cytotoxic effects. Experiments have demonstrated that granulocytes inhibit NK cell constitutive and IL-2 induced cytotoxicity in vitro. Similar to the previously described monocyte-mediated inhibition, treatment with IL-2 and histamine synergistically overcome granulocyte-mediated inhibition (U.S. Pat. No. 5348739; Hellstrand, K., Asea, A., Hermodsson, Histamine-mediated modulation of antibody-dependent cytotoxicity of S. granulocytes, monocytes and natural killer cells, J.Leukoc.biol.55: 392-.

It seems H₂The synergistic effect of the receptor involved in transducing histamine to overcome the granulocyte-mediated inhibition. For example, the effect of histamine on granulocyte-mediated inhibition of antibody-dependent NK cell cytotoxicity is influenced by H₂Receptor antagonist ranitidine, which can be blocked by H₂-receptor agonist dimaprit mimetic. Unlike histamine and IL-2 which completely or almost completely clear monocyte-mediated NK cell inhibition, this treatment only partially cleared granulocyte-mediated NK cell inhibition (U.S. Pat. No. 5348739; Hellstrand, K. et al.

The above experiments indicate that histamine and cytokine therapy is an effective anti-cancer treatment regimen. U.S. patent No.5348739 discloses that administration of histamine and IL-2 to mice prior to inoculation with a melanoma cell line can prevent the formation of lung metastases (metastic foci). This effect is a result of the synergistic interaction of histamine and IL-2, and a significant reduction in melanoma found in mice administered histamine and IL-2, as compared to histamine or IL-2 alone, can be demonstrated.

In addition to the synergistic effect found in the detection of lung metastases, synergistic effect of histamine plus IL-2 treatment was also observed when NK cell cytotoxicity was determined by measuring the killing effect of mice on injected human and mouse malignant tumor cell lines (supra).

In experiments investigating the effect of histamine on NK-dependent cell defense against Herpes Simplex Virus (HSV) type 2, it was found that a single dose of histamine can prolong the survival time of intravenously vaccinated HSV animals, and that the combined administration of histamine and IL-2 has a synergistic effect on the survival time of animals (Hellstrand, k. et al, role of histamine in natural killer cell-dependent protection of mice infected with Herpes Simplex Virus (HSV) type 2. Clin. Diagn. Lab. Immunol.2: 277-280 (1995)).

The above results demonstrate that a combination treatment regimen using histamine and IL-2 is an effective method for treating malignancies and viral infections. E. Synergistic effect of histamine and interferon-alpha

Histamine also acts synergistically with interferon- α to overcome the inhibitory effects of monocytes on NK cell cytotoxicity (Hellstrand et al, biogenic amine modulation of the NK cell response to interferon- α, J.Interferon research, 12; 199-206 (1992)). Like IL-2, interferon- α promotes the cytotoxic effects of NK cells' constitutive NK cells (supra). Monocyte in vitro inhibition interferon-alpha mediated killing of NK cells on malignant tumor target cells is enhanced. Combination therapy of histamine and interferon- α can overcome monocyte-mediated inhibition of NK cell cytotoxic effects. This action of histamine is covered by H₂Blockade by H by a receptor blocker₂-receptor agonist simulation. And H₂Compounds that are structurally similar to the receptor agonist dimaprit but have no agonist activity do not produce a synergistic effect with interferon- α (Hellstrand et al, J. Interferon Res., 12: 199-205 (1992)). F. Combination therapy of histamine, interleukin-2 and interferon-alpha in humans

The results of the in vitro and animal experiments suggest that histamine + IL-2+ interferon-alpha is a promising method for treating human malignant tumors. In fact, combined treatment with histamine, interleukin-2 and interferon- α has been shown to be effective in treating many human malignancies, with response rates found to be significantly increased by 75% compared to IL-2 alone (Hellstrand et al, Experimental study of histamine in advanced melanoma immunotherapy, cancer immunology and immunotherapy, 39: 416-. In the above study, patients received IL-2(Proleukin, Eurocetus) at 18X 10 days 1-5 and 8-12⁶U/m²Constant infusion is repeated every 4-6 weeks with interferon-alpha (6X 10 per day)⁶U, subcutaneous injection). In addition to IL-2, eight patients were given histamine dihydrochloride (1mg, subcutaneous injection) twice daily (supra).

Only one patient in the IL-2 and interferon- α treatment groups exhibited a partial or combined response with a response rate of 14% (1/7). In contrast, the IL-2, interferon- α and histamine combination treatment group showed a corresponding response rate of 75% (6/8). Only two of these patients did not respond (supra).

Thus, histamine + interleukin-2 + interferon- α is an effective anti-tumor therapy. G. Human treatment with histamine + interleukin-2 + chemotherapeutic agents

Recently, the efficacy of treatment of patients with Acute Myeloid Leukemia (AML) using histamine, interleukin-2 and chemotherapeutic drugs was examined (Brune and Hellstrand, maintenance therapy for remission of histamine and interleukin-2 from acute myeloid leukemia, uk journal of hematology, 3 months 1996).

One set of experiments examined the effect of NK cells in killing AML blasts (blasts) in vitro. IL-2 induces NK-mediated cytotoxic effects, but the effects are suppressed by monocytes. In the absence of monocytes, histamine did not affect the IL-2-induced cytotoxic response, but blocked the inhibitory effect of monocytes. However, when H₂Histamine was ineffective in overcoming monocyte inhibition in the presence of the receptor antagonist ranitidine (supra).

In addition, AML patients in remission were treated with histamine + IL-2+ chemotherapeutic drugs cytarabine and thioguanine, and the time to remission was determined and compared to the length of remission before treatment. At the time of publication, patients treated with histamine + IL-2+ cytarabine + thioguanine at position 5 maintained complete remission for a period ranging from 9 to 27 months. The 2 patients relapsed after a remission period lasting 8 and 33 months. The 5 patients began receiving histamine + IL-2+ cytarabine + thioguanine treatment after experiencing remission and relapse, and the duration of remission after treatment regimen exceeded the previous duration of remission (supra). This "time reversal of remission" is rare in the natural progression of AML and the reported incidence is small (< 10%) in AML patients treated with single IL-2 drugs (Shepherd et al, second phase study of secondary partial or complete remission and partial relapse of acute myeloid leukemia by subcutaneous injection of recombinant human (rHU) IL-2, uk journal of hematology S87, 205 (1994)).

Thus, histamine + IL-2+ chemotherapeutic drugs are effective anti-tumor therapies. H. Optimization of histamine administration

Histamine is a strong biologically active molecule with strong biological effects. We have found that an effective amount of a large dose of histamine (bolus) has significant adverse side effects, including flushing, discomfort, increased heart and respiratory rates, hypotension, and severe headaches. Meanwhile, we have found that histamine-mediated therapy has the best effect if it is administered discontinuously over a relatively short period of time, as compared to instillation or controlled release over several days or weeks.

Disclosure of Invention

One embodiment of the present invention is a method of treating a histamine deficient patient comprising the steps of: identifying a patient in need of an increase in histamine levels in circulating blood; administering to the patient an effective amount of histamine in a pharmaceutically acceptable form for a sufficient period of time to achieve a stable level of histamine in the circulating blood. Multiple administrations of histamine are preferred. The histamine is preferably administered at a rate of 0.025 to 0.3 mg/min. A more preferred rate of histamine administration is about 0.1 mg/min. In one aspect, this preferred embodiment histamine is administered over a period of 1-60 minutes, preferably 1-30 minutes. Histamine is preferably administered in a total dose of 0.4-10mg per day; histamine is advantageously administered in a total dose of 0.5-2mg per day. Subcutaneous, intravenous, intramuscular, intraocular, oral, transdermal, intramucosal or rectal administration is preferred.

The present invention also provides a transdermal patch containing histamine, said patch being capable of releasing an effective amount of histamine to a patient in less than about 30 minutes.

Another embodiment of the invention is a solution composition containing about 3 to 50ml of histamine in a pharmaceutically acceptable form packaged in a vial. The composition preferably contains about 10-20ml of solution; more preferred compositions contain about 5ml of solution. The concentration of histamine in the solution is preferably between about 0.01-100 mg/ml. More preferably, the histamine concentration is between about 0.1-50 mg/ml. Most preferably the histamine concentration is between about 1-10 mg/ml. The vial closure is preferably pierceable. The vial is preferably sterile. In another aspect, the solution of this preferred embodiment contains an isotonic carrier and a preservative.

Additional aspects, advantages, and features of the present invention will become apparent to those skilled in the art from the following discussion.

Drawings

Figure 1 shows the possibility of obtaining stable beneficial levels of histamine in circulating blood.

Detailed Description

Prior to the present invention, histamine was considered to have a very short half-life in the blood, expected to be 5 minutes (Beaven, M.A., a factor in the regulation of histamine availability at tissue receptors, see C.R. Gannellin and M.E. parsons, eds: histamine receptor pharmacology, published by Wright PSG, British, UK.103-145 (1982)). The present invention stems from the unexpected discovery that, unlike previous reports, it is possible to stabilize histamine levels in circulating blood for hours or even days following histamine administration. The present invention reports for the first time stable histamine in circulating blood. By involving H₂A regimen of combined administration of a receptor antagonist and histamine, Burtin being able to achieve normal levels of histamine in circulating blood in patients with stable disease of the cancer (Burtine et al, J. European J. Clin. Oncol., 24: 161-167 (1988)). However, the normal histamine levels reported by Burtin may be the result of cancer stabilization, rather than finding stable levels of circulating histamine over time following administration. The normal levels reported by Burtin stem from physiological stability, evidence of which derives from the fact that Burtin reports that normal histamine levels in remission patients fall below normal levels before the patient dies. Burtin does not give a time after administration to determine circulating histamine levels, however, Burtin reports normal levels that appear to be derived from endogenously produced histamine that is stably associated with cancer, rather than finding the sustained presence of exogenously administered histamine.

Cancer patients often exhibit reduced levels of histamine in circulating blood (Burtin et al, reduction of blood histamine levels in solid malignant patients, British J.Cancancer 47; 367- "372 (1983)). Thus, the discovery of stable and favorable blood histamine levels lasting hours or days after histamine administration can be applied to the treatment of cancer and to antiviral agents, based on the synergistic effect of histamine and drugs to promote cytotoxic effector cell-mediated cytotoxicity. In this regimen, cytotoxicity of NK cells and CTLs is enhanced by co-administration of a drug which promotes cytotoxicity by the synergistic effect of histamine and histamine (the stable circulating histamine level obtained after histamine administration is sufficient to enhance the pharmaceutical activity).

In addition, chemotherapy targeted to destroy malignant tumors can result in decreased blood histamine levels. Example 1 below illustrates the reduction in blood histamine levels following treatment with the chemotherapeutic/cytostatic agents cytarabine and thioguanine. alpha-INF also causes decreased histamine levels.

Example 1

Cytarabine (16 mg/m) in 5 AML remission patients²Subcutaneously per day) and thioguanine (40 mg/day, orally) for 21 days or until the platelet count is less than or equal to 50X 10⁹L, histamine levels were determined on whole blood samples 1-5 days before and 1-2 weeks after dosing. Histamine in heparinized venous blood was determined using a radioimmunoassay kit (No. 1051) from biomeica corporation (Newport Beach, CA 92663) and according to the attached instructions.

Histamine levels decreased in all patients after cytostatic treatment (see table below).

Blood histamine levels after treatment of a patient's pre-treatment blood group

Amine levels (. mu.moles/L) (μmoles/L)

1.0.22 can not be detected

2.0.12 can not be detected

3.0.18 can not be detected

4. 0.93 0.38

5. 0.24 0.14

The present invention can be used to restore or maintain beneficial and stable blood histamine levels in patients who have reduced blood histamine levels after chemotherapy.

Beneficial levels of circulating histamine can be obtained by administering histamine before, during, or after treatment with natural killer cell-promoting cytotoxic drugs or chemotherapeutic agents.

Accordingly, the present invention is directed to a method of potentiating the effects of cytotoxic drugs that promote cytotoxic effector cells comprising administering histamine at a stable blood histamine level sufficient to potentiate the cytotoxic promoting effects achieved by said drugs and administering a beneficial amount of said drugs, wherein the cytotoxic promoting effects of said drugs are potentiated. The term "histamine" as used herein includes histamine, its dihydrochloride salt (histamine dihydrochloride), histamine diphosphate, other histamine salts, esters, or prodrugs, and H₂A receptor agonist. Serotonin and 5-HT agonists are also included. Compounds that induce the release of endogenous histamine from the patient's own tissues following administration are also included within the scope of the present invention; thus, the term "histamine" as used herein also includes such compounds.

In one aspect, the invention provides for the administration of histamine prior to the administration of NK cell-promoting and CTLs cytotoxic drugs. In another embodiment, histamine is administered after administration of the pro-cytotoxic agent. In yet another embodiment, histamine is administered during administration of the pro-cytotoxic agent. In yet another embodiment, histamine is administered before, during, and after administration of the pro-cytotoxic agent.

In one embodiment, histamine is administered 1 day prior to administration of the pro-cytotoxic agent. In a preferred embodiment, beneficial and stable circulating blood histamine levels are obtained by administering histamine in doses of 0.4-10mg per day. In yet another preferred embodiment, histamine is administered in a course of 1-4 weeks and the cycle is repeated up to 52 weeks. In a more preferred embodiment, histamine is administered in a course of 1-2 weeks and the cycle is repeated up to 52 weeks. In an embodiment of the invention, the beneficial and stable level of circulating blood histamine concentration is at least 0.2 μmol/L.

In an embodiment of the invention, the cytotoxicity promoting agent has at least one cytokine. The cytokine is preferably interleukin-2. In a preferred aspect of the invention, interleukin-2 is administered at a dose of 0.5-50-80 μ g/kg/day. In another preferred embodiment, interleukin-2 is administered in a course of 1 day to 4 weeks and the cycle is repeated for up to 12 months.

In another embodiment of the invention, the cytokine is interferon- α. The interferon-alpha is preferably administered at a dose of 10,000-200,000U/kg/day. For the treatment of primary melanoma, the preferred interferon-alpha dose is 200,000U/kg/day. For the treatment of other tumors, the preferred interferon- α dose is 50,000U/kg/day. In yet another embodiment, the course of interferon- α administration is up to 18 months. Interferon-alpha is preferably administered in a course of 2-6 weeks and the cycle is repeated up to 12 months.

In yet another embodiment, the cytotoxicity promoting agent comprises interferon- α and interleukin-2.

In another aspect, the method of the present invention for treating a patient having a malignant tumor with histamine and a second effective agent, wherein histamine potentiates the activity of said second effective agent, comprises administering histamine in a pharmaceutically acceptable form to achieve a beneficial blood histamine level, and administering said second effective agent.

In embodiments of this aspect, histamine is administered prior to the administration of the second effective agent. In a preferred embodiment of this aspect, histamine is administered at least 1 day prior to the administration of the second effective agent.

In another embodiment of the invention, histamine is administered after the second effective agent. In yet another embodiment, histamine is administered during the administration of said second effective agent. In yet another embodiment, histamine is administered before, during and after the administration of the second effective agent.

The second potent agent preferably promotes cytotoxicity of NK cells and CTLs.

A third aspect of the present invention is a method for promoting cytotoxicity of NK cells and CTLs, comprising:

a) measuring the patient's blood histamine level to determine whether increasing the patient's blood histamine level promotes cytotoxicity of its NK cells and CTLs;

b) administering histamine in a pharmaceutically acceptable form to a patient whose determination step indicates that increasing the patient's blood histamine level promotes cytotoxicity of their NK cells and CTLs, to achieve a beneficial blood histamine level; and

c) for patients with beneficial blood histamine levels, a second drug is administered to enhance the cytotoxicity of NK cells and CTLs in the patient.

In one aspect, histamine is administered prior to the second agent in the present invention. In a preferred form of this aspect, histamine is administered at least 1 day earlier than the second agent.

In another aspect of the invention, histamine is administered after the second agent. In another embodiment, histamine is administered during the administration of the second agent. In yet another example, histamine is administered before, during, and after administration of the second agent. In each instance, an embodiment of the invention includes an antiviral or antibiotic drug as the second drug.

The invention also includes a method of treating a malignant tumor comprising administering a chemotherapeutic agent to a patient having a malignant tumor and achieving and maintaining a beneficial and stable blood histamine level by administering histamine sufficient to achieve said beneficial and stable blood histamine level.

In one embodiment, histamine is administered prior to the chemotherapeutic agent. In another embodiment, histamine is administered after the chemotherapeutic agent. In yet another aspect of the invention, histamine is administered during the course of chemotherapeutic drug treatment. In yet another embodiment, histamine is administered before, during and after treatment with a chemotherapeutic agent.

It will be appreciated that the patient's circulating blood histamine level may be monitored during treatment and that booster doses (boost) may be administered to achieve a beneficial level whenever its level falls below or near the lower limit of the beneficial level. For example, in this embodiment, histamine should be administered each time the patient's histamine level drops below 0.2. mu. mole/L.

Furthermore, it is understood that histamine should be administered periodically at certain time intervals in a dosage sufficient to establish and maintain beneficial levels.

The route of administration of histamine and cytokines and carrier compositions are disclosed in U.S. patent No.5348739, which is incorporated herein by reference. In addition, methods of administration of chemotherapeutic agents are well established.

In another preferred embodiment, histamine is administered to a patient having a reduced circulating blood histamine level (e.g., less than about 0.2. mu. mole/L). This decreased histamine level may be due to, or be one of the following factors, for example, cancer, viral infection, or other infectious agents. Monocytes and macrophages produce hydrogen peroxide to down-regulate natural killer cells and thereby weaken the immune system's ability to fight infections such as viral infections. Histamine inhibits the production of hydrogen peroxide by monocytes and macrophages. Thus, increasing the stable circulating blood histamine levels in an individual in need of such an increase would be useful for increasing the immune system's ability to fight infections. In a preferred embodiment, beneficial and stable levels of histamine in the circulating blood are obtained by administering a dose of histamine of about 0.2-10 mg/day. In a more preferred embodiment, the course of histamine administration is about one to four weeks. In a most preferred embodiment, the course of histamine administration is about one to two weeks. The time course of histamine administration can be 12 to 18 months. Histamine can be administered either alone or in combination with other therapeutic agents, or in formulations for administration of other agents.

Histamine may be administered at intervals and in dosages sufficient to establish and maintain its beneficial levels. Although the dosage depends on the individual histamine level, as well as other factors, the dosage can be calculated using known dose-response experiments.

For the above treatment, a beneficial histamine level in the blood is at least 0.2 μmol/L.

Stable circulating blood histamine levels

As mentioned before, the basis of the present invention is the discovery of the possibility to obtain beneficial and stable histamine levels in circulating blood. Example 2 describes the stable beneficial levels of histamine in circulating blood obtained after histamine administration. Surprisingly, beneficial histamine levels in the circulating blood can be maintained for a considerable period of time after the histamine administration has been terminated.

Example 2

5 remission AML patients received sterile sodium chloride diluted histamine dihydrochloride (purchased from Apoteksbolaget, Umea, sweden) and bottled human recombinant interleukin-2 (Proleukin, commercially available, Eurocetus, the netherlands) treatment. Histamine and IL-2 were given as subcutaneous injections at different sites for 21 consecutive days, morning and evening. Histamine was administered by subcutaneous injection in a 1ml syringe containing 0.1mg histamine/ml. Histamine is administered twice daily (morning and night) at an injection dose of 0.4-0.7mg histamine per injection (i.e., a total daily histamine dose of 0.8-1.4 mg/day).

IL-2 was administered subcutaneously using 1ml syringes, respectively. IL-2 syringes contain 50. mu.g/mL IL-2. IL-2 was administered twice daily (morning and night) with each injection at a dose of 35-50 μ g of IL-2, i.e., a total daily dose of 70-100 μ g/day.

Peripheral venous blood samples were collected before treatment initiation and one week later in 10ml heparinized tubes.

Samples were taken at least 8 hours after the last injection of histamine and IL-2. The histamine concentration of the whole blood samples was analyzed using a double antibody radioimmunoassay kit (obtained from biomedica, Newport Beach, CA92663 (catalog No.1051)) according to the product instructions provided with the kit (6 months, 1989). Blood histamine levels were measured at the indicated times.

The results of the above experiment are shown in FIG. 1. Values of histamine concentration given in micromoles per liter (mean standard error of the mean).

The patient's blood histamine levels were measured to be less than 0.2. mu. mole/L prior to the experiment. After histamine administration, histamine levels in the circulating blood rise to beneficial levels. Surprisingly, histamine in circulating blood remains high for extended periods of time, even after discontinuation of histamine administration.

Combination therapy with histamine and interleukin-2

The above stable blood histamine levels can be applied in therapy, in which cytotoxicity of NK cells and CTLs is enhanced by the synergistic effect of histamine and a drug promoting cytotoxicity of effector cells. As mentioned previously, interleukin-2 is a cytotoxic enhancer. The stable and beneficial histamine levels obtained with the treatment methods of example 3 and example 4 promote IL-2 activity.

Example 3

Patients with malignant tumors were injected subcutaneously with sterile vehicle solution of histamine in a pharmaceutically acceptable form at a dose of 0.5 mg/day. After one week, IL-2 administration was started when blood histamine levels had risen to at least 0.2. mu. mole/L. Human recombinant IL-2(Proleukin, Eurocetus) was administered as a continuous instillation at 27. mu.g/kg/day on days 1-5 and 8-12.

The above procedure was repeated every 4-6 weeks until regression of the tumor was observed. Treatment continues even if a partial or complete response is observed. For patients who show a complete response, treatment may be given with extended intervals during the treatment week.

Treatment may also include periodic monitoring of histamine levels in circulating blood and, when circulating histamine levels are below 0.2 μmole/L, injecting histamine in a 0.5 mg/day dose in a pharmaceutically acceptable form to return circulating histamine levels above 0.2 μmole/L.

Treatment also includes periodically increasing the level of histamine in the circulating blood by administering 0.5 mg/day of histamine at regular intervals (e.g., every two weeks) for a period of from one to two weeks to maintain the level of histamine in the circulating blood above 0.2 micromole/L.

Example 4

Herpes Simplex Virus (HSV) type 2 infected persons were administered with 27. mu.g/kg/day of human recombinant IL-2(Proleukin, Eurocetus) by continuous instillation on days 1-5 and 8-12. The sterile vehicle solution of histamine in a pharmaceutically acceptable form is injected subcutaneously at a dose of 0.5 mg/day until circulating blood histamine levels of at least 0.2 micromole/L are reached.

The above steps are repeated every 4-6 weeks until a decline in the patient's condition is observed. Even if a partial or complete response is found, treatment continues.

Treatment may also include periodic monitoring of histamine levels in circulating blood and, when circulating histamine levels are below 0.2 μmole/L, injecting histamine in a 0.5 mg/day dose in a pharmaceutically acceptable form to return circulating histamine levels above 0.2 μmole/L.

Treatment also includes periodically raising the level of histamine in the circulating blood by administering 0.5 mg/day of histamine at regular intervals (e.g., every two weeks) for a period of from one to two weeks, to maintain the level of histamine in the circulating blood above 0.2 micromole/L.

If desired, histamine in a pharmaceutically acceptable form in a dose of 0.5 mg/day may also be injected subcutaneously about one week prior to IL-2 treatment to raise circulating histamine levels to at least 0.2. mu. mole/L.

Preferably, histamine is used in combination with interferon-alpha

Another NK cell cytotoxicity promoting agent is interferon- α. The stable and beneficial histamine levels achieved by the treatment described in example 5 may potentiate interferon- α activity.

Example 5

A sterile vehicle solution of histamine in a pharmaceutically acceptable form at 0.5 mg/day is administered subcutaneously to patients with malignant tumors or patients with early tumor resection. One week later, interferon- α administration was initiated when histamine levels in circulating blood were increased to at least 0.2 μmole/L. The interferon is administered in a sterile vehicle solution at a dose of 50,000U/kg/day for 2-6 weeks.

The above treatments were repeated 3 times per week, or even several times per day for a total of 24 months, until tumor regression was observed in the patients. Treatment with histamine, IL-2 and interferon continues even if a partial or complete response is found. For patients with complete responses, the intermittent time during the treatment week can be extended.

Treatment may also include periodic monitoring of histamine levels in the circulating blood and, when circulating histamine levels are below 0.2 μmole/L, supplementary injection of histamine in a dose of 0.5-2.0 mg/day in a pharmaceutically acceptable form to restore histamine levels in the circulating blood to above 0.2 μmole/L.

Treatment may also include periodically raising the level of histamine in the circulating blood by administering 0.5 mg/day of histamine at regular intervals (e.g., every two weeks) for a period of one to two weeks, to maintain the level of histamine in the circulating blood above 0.2 micromole/L.

In addition, the number of administrations of interferon- α may vary depending on the tolerance and efficacy of the treatment to the patient. For example, interferon may be administered three times a week, even daily, for a total of 24 months. Those skilled in the art are familiar with the modification of interferon therapy to achieve beneficial therapeutic effects while providing patient comfort.

Example 6 describes a therapeutic approach to obtain stable and beneficial histamine levels that promote interferon- α activity in antiviral treatments.

Example 6

Histamine and interferon- α were administered in a pharmaceutically acceptable form to patients with hepatitis c in a subcutaneous injection at 0.5 mg/day. Histamine was administered at 0.5-2.0mg daily to maintain histamine levels in circulating blood above 0.2 μmole/L. Interferon in a suitable sterile carrier solution was administered at a dose of 50000U/kg/day.

The above treatment is repeated 3 times per week, or even several times per day for a total of 24 months, until normal levels of liver enzymes in the serum are observed and viral RNA is cleared from the serum. Treatment with histamine and interferon continues even if a partial or complete response is found.

The treatment may further comprise periodically monitoring the level of histamine in the circulating blood and, when the level of histamine in the circulation is below 0.2 μmole/L, injecting a supplementary amount of histamine in a pharmaceutically acceptable form in a dose of 0.5-2.0 mg/day to restore the level of histamine in the circulating blood to above 0.2 μmole/L.

Treatment may also include periodically raising the level of histamine in the circulating blood by administering histamine at regular intervals (e.g. every two weeks) for a period of from one to two weeks at 0.5-2.0 mg/day to maintain the level of histamine in the circulating blood above 0.2 micromole/L.

Histamine may also be injected subcutaneously at a dose of 0.5 mg/day in a pharmaceutically acceptable form about one week prior to interferon-c treatment to raise the level of histamine in the circulating blood to at least 0.2 μmole/L.

In addition, the frequency of interferon- α administration can be varied depending on the tolerance and efficacy of the treatment by the patient. For example, interferon may be administered three times a week, even daily, for a total of 24 months. Those skilled in the art are familiar with the modification of interferon therapy to achieve beneficial therapeutic effects while providing patient comfort.

Histamine, IL-2 and interferon-alpha in combination

Beneficial and stable levels of histamine in circulating blood may also be used in combination with treatments involving several NK cell toxicity promoting agents. Example 7 describes the administration of this treatment.

Example 7

Human recombinant IL-2(Proleukin, Eurocetus) was administered by continuous instillation for 1-5 and 8-12 days to patients with malignant tumors or to virus-infected patients, such as hepatitis B, hepatitis C, Human Immunodeficiency Virus (HIV), Human Papillomavirus (HPV), Herpes Simplex Virus (HSV) type 1 or 2-infected patients at 27. mu.g/kg/day. In addition, the patients also received 6X 10 daily⁶U doses of interferon-alpha, and 0.5-2.0 mg/day of histamine in a pharmaceutically acceptable form. Histamine is administered for 1-2 weeks until the level of histamine in the circulating blood reaches above 0.2 μmole/L.

The above treatment is repeated every 4-6 weeks until regression of the patient's tumor is observed, or until improvement in viral infection occurs. Treatment continues even if a partial or complete response is found in the patient. For patients with complete responses, the intermittent time during the treatment week can be extended.

Treatment may also include periodic monitoring of histamine levels in the circulating blood and injection of 0.5-2.0mg of histamine in a pharmaceutically acceptable form per day for one to two weeks to restore histamine levels in the circulating blood above 0.2 μmole/L when the circulating histamine levels are below 0.2 μmole/L.

Treatment may also include periodically increasing the level of histamine in circulating blood by administering histamine on a regular intermittent basis, such as every other day, every second week, or every other week.

Histamine in a pharmaceutically acceptable form (in, e.g., a sterile carrier solution) can be injected subcutaneously about one week prior to the initiation of IL-2 and interferon- α administration, 0.5-1.0mg per injection, 1-4 times per day, to raise circulating histamine levels to at least 0.2 μmole/L.

In addition, the frequency of interferon- α administration may vary depending on the tolerance and efficacy of the patient to the treatment. For example, interferon is administered weekly, even three times per day for a total of 24 months. Those skilled in the art are familiar with the modification of interferon therapy to achieve beneficial therapeutic effects while providing patient comfort.

Combination of histamine and chemotherapeutics

Histamine may also be used in combination with chemotherapeutic agents. Generally, histamine levels in circulating blood decline during chemotherapy. Low levels of circulating histamine can result in suppression of NK cell cytotoxicity by monocytes. Administration of histamine prior to, during, or after chemotherapy to restore normal levels of circulating histamine can abrogate monocyte-mediated inhibition.

Accordingly, the present invention contemplates the restoration of histamine levels in circulating blood to normal levels in combination with chemotherapeutic agents. In addition, the treatment may include administration of IL-2 and/or interferon- α.

Representative drugs for cancer therapy include cyclophosphamide, chlorambucil, melphalan, estramustine, ifosfamide, prednimustine, marianid, thiotepa, carmustine, lomustine, methotrexate, azathioprine, mercaptopurine, thioguanine, cytarabine, fluorouracil, vinblastine, vincristine, vinblastine amide, etoposide, actinomycin D, doxorubicin, daunorubicin, epirubicin, bleomycin, mitomycin (nitomomycin), cisplatin, carboplatin, procarbazine, amacrine, mitoxantrone, tamoxifen, nilutamide, and aminoglutethimide. Methods for treating malignant tumors using these compounds are well established. In addition, other compounds for treating cancer may also be employed in the present invention.

Malignancies in therapeutic indications include, but are not limited to, primary or metastatic malignant diseases, hematologic malignancies such as acute or chronic myelogenous leukemia, acute or chronic lymphocytic leukemia, multiple myeloma, waldenstrom's macroglobulinemia, hairy cell leukemia, myelodysplastic syndrome, polycythemia (polycythemia), and essential thrombocythemia.

As mentioned previously, histamine + IL-2 has been shown to be effective in the treatment of acute myeloid leukemia in combination with traditional chemotherapy (Brune and Hellstrand, J.UK.Hematology, 3 months 1996). The method of using the present invention in combination with chemotherapeutic agents and IL-2 is shown in example 8. It is understood that beneficial and stable levels of circulating histamine may also be utilized when treated with chemotherapeutic agents alone.

Example 8

For AML patients in primary, secondary, or complete remission, IL-2 is administered (subcutaneously) at 35-50. mu.g (equivalent to 6.3-9X 10)⁵IU), treatment course is 21 days, twice a day]The treatment course was repeated with 6 weeks between courses, and continued until recurrence. In the first course of treatment, the patient receives a low dose chemotherapy for 3 weeks, including 16mg/m²Cytarabine per day and thioguanine 40mg per day. Thereafter, the patient is injected subcutaneously with 0.5mg of histamine in a pharmaceutically acceptable form daily for one week to raise circulating histamine to a steady beneficial level above 0.2 μmole/L. Subsequently, the patient received 100. mu.g of interleukin-2 per day for a period of 3 weeks. In the second week of this period, 0.5mg of histamine in a pharmaceutically acceptable form is administered daily to raise the circulating histamine levels to beneficial levels. The patient is then allowed to rest for one to six weeks.

After the rest period of the first course, a second course begins. Twice daily, each subcutaneous injection of 0.5mg of histamine in a pharmaceutically acceptable form in a sterile carrier solution until circulating histamine levels of at least 0.2 micromole/L are reached. Cytarabine (subcutaneous injection 16 mg/m)²Daily) and thioguanine (40 mg/day orally) for 21 days (or until a platelet count of 50X 10⁹L). In the middle week, the patient is injected twice daily with 0.5 mg/dose of histamine in a pharmaceutically acceptable form so that circulating histamine rises to beneficial levels. At the end of the third week of chemotherapy, patients injected histamine twice daily in a dose of 0.5mg per time in a pharmaceutically acceptable form for one week. Subsequently, the patient receives the drug dailyThe period of receiving 100. mu.g of interleukin-2 was 3 weeks. During the three weeks of IL-2 treatment described above, circulating histamine levels were elevated in the middle week. The patient is allowed to rest for two to six weeks.

Thereafter, a third course of treatment is initiated. The third treatment course is the same as the second treatment course.

In addition, circulating histamine levels can be periodically monitored by the above method and histamine is administered to maintain blood histamine at a beneficial level above 0.2 μmole/L each time the circulating histamine levels fall below a necessary level. In addition, histamine may be administered periodically during the treatment period to maintain beneficial circulating levels. Histamine may also be administered in implants or in controlled release formulations.

Example 9

For example, 0.2-2.0mg per day of histamine in a pharmaceutically acceptable form is administered to a patient having low levels of circulating blood histamine (i.e., 0.2 μ M or less) associated with a malignancy or a virus such as hepatitis B, hepatitis C, Human Immunodeficiency Virus (HIV), Human Papilloma Virus (HPV), Herpes Simplex Virus (HSV) type 1 or type 2 infection. Histamine is administered for a period of one to two weeks until histamine levels in the circulating blood reach above 0.2 μmole/L.

The above treatment is repeated every 4-6 weeks until regression of the patient's tumor is observed, or until improvement in viral infection occurs. Treatment continues even if a partial or complete response is found in the patient. For patients with complete responses, the intermittent time during the treatment week can be extended.

The treatment may further comprise periodically monitoring the level of histamine in the circulating blood and, when the level of circulating histamine is below 0.2 μmole/L, injecting 0.2-2.0mg of histamine in a pharmaceutically acceptable form daily for one to two weeks to restore the level of histamine in the circulating blood to above 0.2 μmole/L.

Treatment may also include periodically increasing the level of histamine in the circulating blood by administering histamine at regular intervals, such as on a day, two weeks, or a week.

Histamine in a pharmaceutically acceptable form, such as a sterile carrier solution, can be injected subcutaneously 0.5-1.0 mg/time, 1-4 times per day, to raise circulating histamine levels to at least 0.2. mu. mole/L.

Optimal release of histamine

Controlled release carriers are well known to those skilled in the art of pharmacy. Technologies and products in this field generally refer to controlled release, sustained release, delayed action, implants, drug reservoirs (reposititors), sustained release, delayed release and timed release; the term "controlled release" as used herein is meant to encompass the foregoing techniques.

Various controlled release carriers are known, including biodegradable or bioerodible (bioerodable) polymers such as polylactic acid, polyglycolic acid, regenerated collagen. Known controlled release drug delivery designs include tablets, capsules, gels, microspheres, liposomes, ocular implants, micropumps, and other delivery devices such as pumps and syringes. Implantable or injectable polymer matrices and transdermal formulations from which the active ingredient is slowly released are also known and may be used in the present invention.

Suitable input devices for use with the present invention include syringe pumps, auto-injector systems, and micro-pumps. Examples of such input devices include model 30 mobile administration Pump (AmBulatory Infusion Pump DriVe) available from Microject, salt lake, Utah and Baxa injection input devices available from Baxa, Inc., Engliwood, Colorado. Any system capable of releasing histamine in the manner described below may be used in the method of the present invention.

The infusion device of the present invention preferably contains an effective amount of histamine, histamine dihydrochloride, histamine phosphate, serotonin (5HT agonist), H₂A receptor agonist or a substance that induces the release of a therapeutically effective amount of endogenous histamine. The input device may be pre-loaded with the desired substance at the time of manufacture, or the input device may be filled with the substance just prior to use. Prefilled drug delivery pumps and syringe pumps are well known to those skilled in the art. If necessary, active substanceThe matrix may be part of a formulation comprising a controlled release carrier. The controlled release device used in the infusion device controls the rate of administration and the amount of administration. The controlled release substance may be incorporated into the device or be a separate entity. It may be pre-configured in production or configured just prior to use. Those skilled in the art are familiar with these controlled release devices and their use in delivery devices.

Oral controlled release formulations are also well known. The active compound is bound to a dissolvable or erodible matrix. Hydrophilic gums, such as hydroxymethyl cellulose, are commonly employed. Lubricants such as magnesium stearate, stearic acid, or calcium stearate may be used as an aid in the tableting process.

For parenteral administration, histamine or a compound that induces the release of endogenous histamine may be combined with distilled water, preferably buffered to an appropriate pH and containing an appropriate (e.g., isotonic) concentration of salt. The histamine preparations given may be solutions or powders which are reconstituted just before use. They may also be provided in pre-packaged vials, injection needles, or injection systems.

For administration to individuals in need of elevated levels of histamine from circulating blood, histamine may also be provided in vials sealed with septa (septa) ranging in volume from 3 to 50 ml. In preferred embodiments, vials contain volumes of 3, 5, 6, 8, 10 and 20 ml. The vial is preferably sterile. The vial may optionally contain an isotonic carrier medium and/or a preservative. The desired final concentration of histamine can be given according to any desired amount of histamine. In a preferred embodiment, the histamine concentration is between about 0.01mg/ml and 100 mg/ml. More preferably, the histamine concentration is between about 0.1mg/ml and 50 mg/ml. The most preferred histamine concentration is between about 1mg/ml and 10 mg/ml. For the lower end of the volume range, single dose administration is preferred, and for the upper end of the volume range, multiple dose administration is preferred.

Controlled release formulations can be achieved by complexing or adsorbing histamine with a polymer. Controlled release delivery can be achieved by selecting appropriate macromolecules such as polyesters, polyamino acids, polyvinylpyrrolidone, ethylene vinyl acetate, methylcellulose, carboxymethylcellulose, and protamine sulfate, and the concentration and combination of these macromolecules selected to control the release of the active agent.

The hydrogel may be prepared by copolymerization of a hydrophilic monoolefinic monomer such as ethylene glycol methacrylate, in which the histamine compound dispersed in the liquid component is gradually released over time. Matrix devices may be employed in which histamine is dispersed in a carrier substance of the matrix. The carrier may be porous, non-porous, solid, semi-solid, permeable or impermeable. In addition, a central histamine containing chamber comprising a rate controlling membrane wrap may be employed to control histamine release. The speed control film comprises ethylene-vinyl acetate copolymer or butylene terephthalate/tetramethylene terephthalate. Also included are silicone rubber implants.

In a preferred embodiment, transdermal patches (patches) with a steady state reservoir layer sandwiched between a water impermeable backing layer and a pellicle and transdermal formulations are also used for histamine and histamine agonist administration. Transdermal delivery systems are well known in the art. Closed transdermal patches for dermal or mucosal administration of active drugs are disclosed in U.S. patent nos. 4573996, 4597961 and 4839174, which are incorporated herein by reference. One type of transdermal patch is a polymer matrix in which the active agent is dissolved and through which the active ingredient diffuses to the skin. Such transdermal patches are disclosed in U.S. patent nos. 4839174, 4908213 and 4943435, which are incorporated herein by reference.

The transdermal patch system of the present invention is designed to release the drug in a relatively small dose over a relatively long period of time (up to several days or weeks), whereby the present invention specifically delivers an effective dose of histamine in accordance with the dose in the range of 2-60 minutes, preferably the dose is administered within about 30 minutes. These patches allow for rapid and controlled release of histamine. Rate-controlling microporous outer membranes, or microcapsules (micropockets) of histamine dispersed in a silicone polymer matrix, may be employed to control the rate of release. These speed control methods are described in U.S. patent No.5676969, which is incorporated herein by reference. In another preferred embodiment, histamine is released from the patch to the skin of the patient in about 30 minutes or less. In a preferred embodiment, histamine is released from a patch in an amount of about 0.2mg to about 3mg per tablet at a rate of about 0.025mg to about 0.3mg per minute. More preferred embodiments are those wherein the patch contains about 0.7 to about 1.5 mg.

These transdermal patches and formulations may or may not employ a penetration enhancer such as dimethyl sulfoxide (DMSO), sulfoxide or phosphorus oxide in combination with sucrose fatty acid ester, eugenol or Azone. The use of electrolytic transdermal patches is also included within the scope of the present invention. Electrolytic transdermal patches are described in U.S. patent nos. 5474527, 5336168, and 5328454, the entire contents of which are incorporated herein by reference.

Another possible method of controlling histamine release is to bind histamine to polymer particles such as polyesters, polyamino acids, hydrogels, polylactic acid or ethylene vinyl acetate polymers.

Furthermore, in addition to binding histamine to these polymeric particles, histamine may be encapsulated in microcapsules, e.g. microcapsules prepared by coacervation techniques, or by interfacial polymerization, e.g. in hydroxymethylcellulose or gelatin-microcapsules, respectively, or in colloidal drug delivery systems, e.g. liposomes, albumin microspheres, microemulsions, nanoparticles, nanocapsules (nanocapsules), or macroemulsions. These techniques are well known to the skilled pharmaceutical person.

Histamine is preferably injected, instilled or released to the patient at a rate of about 0.025-0.2 mg/minute. A rate of about 0.1mg/min is preferred. Preferred histamine administration times are from about 1, 3 or 5 minutes to about 30 minutes, with a preferred upper limit of about 20 minutes, such that the total daily dose for an adult ranges from about 0.4 to 10.0mg, and preferably 0.5 to 2.0 mg. It has been found that histamine administered for longer periods of time, i.e., longer than 30 minutes, results in reduced or ineffective drug efficacy, while rapid administration within 1-3 minutes causes more significant and serious side effects including allergies, heart failure, bronchospasm, marked flushing, malaise, accelerated heart and respiration, hypotension, and severe headaches.

Each dose of histamine may be administered once daily up to about four times daily, and preferably twice daily. Administration can be subcutaneous, intravenous, intramuscular, intraocular, oral, transdermal, intranasal, or intrarectal, and can be by direct subcutaneous or other means of injection or instillation, or indirect according to a controlled release mechanism of the type previously described. Any controlled release carrier or delivery device capable of administering a therapeutically effective amount of histamine over a period of about 1-30 minutes may be used. In a preferred embodiment, intranasal administration is achieved by introducing the histamine solution therein into the nasal cavity using a nebulizer or atomizer which produces a fine mist. For rectal administration, histamine is formulated as suppositories using methods well known in the art.

Except for histamine, histamine dihydrochloride, histamine phosphate, other histamine salts, esters, homologs (conjugates), prodrugs, and H₂In addition to receptor agonists, the use of serotonin, 5HT agonists, and compounds that induce histamine release from the patient's own tissues are also within the scope of the invention. Retinoic acid, other retinoids such as 9-cis-retinoic acid and all-trans retinoic acid, IL-3, and ingestible allergens are known to be compounds capable of inducing the release of endogenous histamine. These compounds can be administered to a patient by oral, intravenous, intramuscular, subcutaneous, and other suitable routes. However, the rate of administration should be such that endogenous histamine is released in the range of about 0.05-2.0 mg/min.

Each dose of the histamine release-inducing compound may be administered once daily to about four times daily, preferably twice daily. Can be administered subcutaneously, intravenously, intramuscularly, intraocularly, orally, or transdermally, and can be administered in combination with a controlled release mechanism of the type previously described. Any controlled release carrier capable of administering a therapeutically effective amount of a compound that induces histamine release over a period of about 1-30 minutes may be used.

Claims (7)

1. Use of histamine for the preparation of a transdermal patch for the treatment of histamine deficient individuals comprising:

a transdermal patch is provided comprising an effective amount of histamine dissolved in a polymer matrix in a pharmaceutically acceptable form, wherein the transdermal patch administers multiple doses of histamine over a period of time sufficient to achieve a stable level of histamine in the circulating blood of the individual.

2. The use of claim 1, wherein the histamine is administered at a rate of 0.025 to 0.3 mg/min.

3. The use of claim 1, wherein the histamine is administered at a rate of 0.1 mg/min.

4. The use of claim 1, wherein the histamine is administered over a period of 2 to 60 minutes.

5. The use of claim 4, wherein the histamine is administered over a period of between 2 and 30 minutes.

6. The use of claim 5, wherein said histamine is administered in a total daily dose of between 0.4-10 mg.

7. The use of claim 5, wherein said histamine is administered in a total daily dose of between 0.2-2 mg.