quifenadine

Quifenadine is a second-generation antihistamine and a derivative of quinuclidylcarbinol. It acts primarily as a competitive blocker of histamine H1 receptor in peripheral tissues and also activates the enzyme diamine oxidase (histaminase), which helps break down endogenous histamine[1][3][6]. This dual mechanism reduces histamine concentration in tissues and explains its efficacy even in patients unresponsive to other antihistamines[5]. Quifenadine is indicated for the treatment of allergic conditions such as pollinosis (hay fever), acute and chronic urticaria, allergic rhinitis, allergic conjunctivitis, angioedema, various dermatoses (eczema, neurodermatitis), pruritus, and allergic reactions caused by food or medicines[1][5]. Additionally, it exhibits antiarrhythmic properties—likely due to its influence on calcium channels and potassium channel activity—making it useful in children with frequent premature beats without significant QT prolongation or sinus node depression[3][8]. The drug does not have a marked depressant effect on the central nervous system but may cause mild sedation in some cases[5].

Brand names

Phencarol

Other names

QuifenadinumQuifenadinoquifenadine hydrochloride