clemastine /klemas″tēn/ , an antihistamine. ▪ INDICATIONS: It is prescribed in the treatment of symptoms of allergic rhinitis, pruritus, or conjunctivitis. ▪ CONTRAINDICATIONS: Use by lactating mothers or those undergoing monamine oxidase inhibitor therapy or having known sensitivity to this drug or other antihistamines is contraindicated. It is also contraindicated with narrow-angle glaucoma, asthma, symptomatic prostatic hypertrophy, and bladder-neck destruction. ▪ ADVERSE EFFECTS: Among the most serious adverse reactions are hypersensitivity, skin rash, and tachycardia. Transient drowsiness commonly occurs.