Methapyrilene is an

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

and

anticholinergic Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system. These agents inhibit the parasympatheti ...

of the

pyridine Pyridine is a basic (chemistry), basic heterocyclic compound, heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom . It is a highly flammable, weak ...

chemical class Chemical classification systems attempt to classify elements or compounds according to certain chemical functional or structural properties. Whereas the structural properties are largely intrinsic, functional properties and the derived classi ...

which was developed in the early 1950s. It was sold under the trade names Co-Pyronil and Histadyl EC in the UK. It has relatively strong

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

effects, to the extent that its primary use was as a medication for

insomnia Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...

rather than for its antihistamine action. Together with

scopolamine Scopolamine, also known as hyoscine, or Devil's Breath, is a medication used to treat motion sickness and postoperative nausea and vomiting. It is also sometimes used before surgery to decrease saliva. When used by injection, effects begin a ...

, it was the main ingredient in Sominex, Nytol, and Sleep-Eze. It also provided the sedative component of Excedrin PM. All of these products were reformulated in the late 1970s when methapyrilene was demonstrated to cause

liver cancer Liver cancer, also known as hepatic cancer, primary hepatic cancer, or primary hepatic malignancy, is cancer that starts in the liver. Liver cancer can be primary in which the cancer starts in the liver, or it can be liver metastasis, or secondar ...

in rats when given chronically.

References

Hepatotoxins Sedatives Thiophenes 2-Pyridyl compounds H1 receptor antagonists Dimethylamino compounds {{sedative-stub

See also

References