11 Facts About Doxylamine

Doxylamine, sold under the brand name Unisom among others, is an antihistamine medication which is used in the treatment of insomnia and allergies.

Doxylamine is available over-the-counter, and is used in nighttime cold medicines, such as NyQuil, as well as in pain medications containing acetaminophen and codeine, to help with sleep.

Doxylamine is an antihistamine—specifically an inverse agonist of the histamine H1 receptor—and to a lesser extent an anticholinergic—specifically an antagonist of the muscarinic acetylcholine receptors M1 through M5.

Doxylamine is an antihistamine used to treat sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.

Doxylamine is available alone as immediate-release oral tablets containing 25mg doxylamine succinate.

Doxylamine alone is available over-the-counter, whereas doxylamine in combination with pyridoxine is a prescription-only medication.

Doxylamine is a potent anticholinergic and has a side-effect profile common to such drugs, including blurred vision, dry mouth, constipation, muscle incoordination, urinary retention, mental confusion, and delirium.

Doxylamine is metabolized in the liver primarily by the cytochrome P450 enzymes CYP2D6, CYP1A2, and CYP2C9.

Doxylamine is a member of the ethanolamine class of antihistamines.

Doxylamine is a first-generation antihistamine and was discovered by Nathan Sperber and colleagues and was first reported in 1948 or 1949.

Doxylamine is primarily used as the succinic acid salt, doxylamine succinate.