Phenbenzamine, sold under the brand name Antergan and known by the former developmental code name RP-2339, is an antihistamine of the

ethylenediamine Ethylenediamine (abbreviated as en when a ligand) is the organic compound with the formula C2H4(NH2)2. This colorless liquid with an ammonia-like odor is a basic amine. It is a widely used building block in chemical synthesis, with approximately ...

class which also has anticholinergic properties. It was introduced in 1941 or 1942 and was the first antihistamine to be introduced for medical use. Soon following its introduction, phenbenzamine was replaced by another antihistamine of the same class known as

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

(pyrilamine; Neoantergan). Following this, other antihistamines, such as diphenhydramine, promethazine, and

tripelennamine Tripelennamine, sold under the brand name Pyribenzamine by Novartis, is a drug that is used as an antipruritic and first-generation antihistamine. It can be used in the treatment of asthma, hay fever, rhinitis, and urticaria, but is now less co ...

, were developed and introduced. Owing to their

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ...

effects, phenbenzamine and promethazine were assessed in the treatment of manic depression in France in the 1940s and were regarded as promising therapies for such purposes. Whereas phenbenzamine was the first clinically useful antihistamine, piperoxan was the first compound with antihistamine properties to be discovered and was synthesized in the early 1930s.

Chemistry

Synthesis

Phenbenzamine can be prepared by the reaction of ''N''-benzylaniline with 2-chloroethyldimethylamine. : Phenbenzamine synthesis

References

Abandoned drugs Anilines category:Diamines H1 receptor antagonists Sedatives {{Respiratory-system-drug-stub