Rebecca Romijn and Jerry O'Connell play husband and wife. They are also married in real-life.
The chant that the coven is using when attempting to hex Judi is (slight pronunciation differences aside) the Charm of Making from John Boorman's Excalibur (1981)
Wal-Mart altered the slipcover of the Blu-Ray release of the film. They shortened the title to "Panic". However, the actual box art underneath retains the actual title.
The opening scene is a reference to the opening of John Carpenter's Halloween - La notte delle streghe (1978). The female characters in both are named Judith.