Doctors refer to hair loss that occurs as a side effect of medication as drug-induced alopecia. Hair loss can be a side effect of many different medications, such as those for chemotherapy.
Alopecia is the medical term for hair loss. Many different factors contribute to this condition, including certain medications.
Drug-induced alopecia can affect any part of the scalp or body. The extent and duration of hair loss depend on the medication that the person is taking, as well as the dosage.
The effects of drug-induced alopecia often appear within 3 months of an individual starting on a particular medication.
A person who experiences drug-induced alopecia may notice thinning hair. The hair loss may be more apparent on the top of the scalp.
Other early signs of alopecia include a noticeable increase in the number of shed hairs in hairbrushes, shower drains, and on pillows.
Drugs that have an association with hair loss include:
- amphetamines
- selective serotonin reuptake inhibitors (SSRIs), such as paroxetine (Paxil), fluoxetine (Prozac), and sertraline (Zoloft)
- other psychiatric medications, including antipsychotics and tricyclic antidepressants
- monoclonal antibodies targeting cytokines, such as tumor necrosis factor-alpha (infliximab) and interleukin 4 (dupilumab)
- immune checkpoint inhibitors
- epidermal growth factor receptor tyrosine kinase inhibitors, such as erlotinib and gefitinib
- angiotensin converting enzyme (ACE) inhibitors
- antifungal medications,
such as fluconazole - beta-blockers, which doctors use to treat heart problems and glaucoma
- birth control pills
- blood thinners, including heparin and warfarin (Coumadin)
- cholesterol lowering drugs, such as gemfibrozil (Lopid)
- hormone replacement therapy (HRT)
- isotretinoin (Accutane) and other vitamin A-based medications
- levodopa (Atamet) and other medications for Parkinson’s disease
- steroids
- naproxen (Naprosyn) and other nonsteroidal anti-inflammatory drugs (NSAIDs)
Colchicine (Colcrys), which doctors use to treat gout, can also sometimes cause the loss of hair in the growing stage.
Chemotherapy medications and hair loss
Not all chemotherapy drugs will cause hair loss. According to the Canadian Cancer Society, the drugs that are more likely to cause hair loss include:
- dactinomycin
- cyclophosphamide
- daunorubicin
- doxorubicin
- etoposide
- docetaxel
- eribulin
- ifosfamide
- idarubicin
- paclitaxel
- topotecan
- irinotecan
Hair loss can begin within 2 to 4 weeks of starting chemotherapy. However, individuals who receive the same drugs and undergo the same treatment can still have different hair loss experiences.
Hair loss due to medication can be temporary, and the hair will begin to grow back once a person has stopped taking it. However, people should not stop taking a medication without their doctor’s agreement.
The doctor will discuss any alternative treatment options and ensure that a person switches to any new medications safely.
The time it takes for the hair to regrow will differ for each person. For example, it can take 2 to 6 months for the hair to begin to grow back after stopping chemotherapy.
People who think that they may be experiencing drug-induced alopecia need to consult a healthcare professional.
When diagnosing drug-induced alopecia, a doctor will take a complete medical history that takes into account the following factors:
- any new medications that the person is taking, including over-the-counter drugs and supplements
- any change in medication dosages
- the person’s general health and nutrition status
- whether the person has had any recent illnesses or surgeries
- whether there is a family history of hair loss
A doctor may also perform the following tests to assist with the diagnosis:
- Hair pull test and examination: This involves pulling on a small section of the hair to see how many strands come away from the scalp.
- Scalp analysis: The doctor will examine the scalp for signs of flaking, skin discoloration, and hair loss.
- Scalp biopsy: This involves taking skin samples from areas of the scalp where hair loss has occurred and analyzing them. The results can alert the doctor to other possible causes of alopecia.
- Blood tests: These tests can reveal any nutritional or hormonal imbalances that may be causing hair loss.
Certain medications can cause hair loss during different phases of the hair growth cycle.
People who notice a significant increase in hair loss when taking a medication should contact a doctor. The doctor may be able to lower the dosage of the medication or prescribe an alternative that is less likely to cause hair loss.
Most of the time, drug-induced alopecia is reversible. A person’s hair usually starts growing back a few months after they stop taking the medication.