Buy Mepyramine (pyrilamine) Cas 91-84-9

Mepyramine, also known as pyrilamine, is a first-generation antihistamine, targeting the H₁ receptor as an inverse agonist.^[1] Mepyramine rapidly permeates the brain, often causing drowsiness.^[2] It is often sold as a maleate salt, pyrilamine maleate.

The medication has negligible anticholinergic activity, with 130,000-fold selectivity for the histamine H₁ receptor over the muscarinic acetylcholine receptors (for comparison, diphenhydramine had 20-fold selectivity for the H₁ receptor).^[3]

It was patented in 1943 and came into medical use in 1949.^[4] It was marketed under the names Histadyl, Histalon, Neo-Antergan, Neo-Pyramine, and Nisaval.^[5] In the 1960s and 70s it was a very common component in over-the-counter sleep aids such as Alva-Tranquil, Dormin, Sedacaps, Sominex, Nytol, and many others.^[5] The US Food and Drug Administration (FDA) included it in the list of chemicals and compounds barred from use in over-the-counter (OTC) nighttime sleep aid products in 1989.^[6]

It is used in over-the-counter combination products to treat the common cold and menstrual symptoms such as Midol Complete.^[7] It is also the active ingredient of the topical antihistamine creams Anthisan^[8] and Neoantergan^[1] sold for the treatment of insect bites, stings, and nettle rash.

• Chloropyramine