cyclizine hydrochloride /sī″klizēn/ , an antihistamine and antiemetic/antivertigo agent. ▪ INDICATIONS: It is prescribed in the treatment or prevention of motion sickness or vertigo. ▪ CONTRAINDICATIONS: Known hypersensitivity to this drug prohibits its use. It is not given to newborns or lactating mothers. ▪ ADVERSE EFFECTS: Among the more serious adverse reactions are skin rash, hypersensitivity reactions, and tachycardia. Drowsiness, dryness of the mouth, and worsening vision occur commonly.