ABSTRACT
Homatropine is a synthetic tertiary amine alkaloid and an anticholinergic drug that acts as an antagonist at muscarinic acetylcholine receptors, blocking parasympathetic nerve stimulation. It is present in antitussives in combination with hydrocodone (dihydrocodeinone) bitartrate indicated for the symptomatic relief of cough. This chapter provides monographs of homatropine which have caused contact allergy/allergic contact dermatitis. The monographs present: identification section; contact allergy (general population, patients with dermatitis, case reports and case series); cross-reactions; patch test sensitization; photocontact allergy; and immediate contact reactions (contact urticaria). The identification section presents IUPAC names, synonyms, CAS and EC numbers, structural and chemical formulas, Merck Index monographs, and advises on patch testing. The chapter also covers an extensive amount of information to benefit dermatologists, allergists, and all others interested in drug allergy.
