(E/Z)-doxepin

Doxepin is a medication belonging to the tricyclic antidepressant (TCA) class of drugs used to treat major depressive disorder, anxiety disorders, difficult-to-treat chronic urticaria, and insomnia. For hives it is a less preferred alternative to antihistamines. It has a mild to moderate benefit for sleeping problems. It is used as a cream for itchiness due to atopic dermatitis or lichen simplex chronicus.

Common side effects include sleepiness, dry mouth, constipation, nausea, and blurry vision. Serious side effects may include increased risk of suicide in those under the age of 25, mania, and urinary retention. A withdrawal syndrome may occur if the dose is rapidly decreased. Use during pregnancy and breastfeeding is not generally recommended. Although how it works for treating depression remains an area of active inquiry, it may involve increasing the levels of norepinephrine, along with blocking histamine, acetylcholine, and serotonin.