This drug may cause drowsiness, somnolence and blurred vision, if affected, do not drive or operate machinery. Remove contact lenses prior to ophth admin and reinsert after 10-15 min.
Symptoms: Drowsiness, confusion, nystagmus, dyspnoea, bradycardia or tachycardia, disorientation, headache, hypotension, reversible coma; hyperexcitability or convulsions (childn). Management: Symptomatic and supportive treatment. Perform gastric lavage immediately following ingestion. Admin of activated charcoal w/in approx 1 hr following ingestion. Monitor CV function. May give short acting barbiturates or benzodiazepines in case of excitation.
May potentiate effects of sedatives, hypnotics and antihistamines. Potentially Fatal: Reduced platelet count with oral antidiabetics.
May potentiate effects of alcohol.
Description: Ketotifen is a histamine H1-receptor antagonist and a mast cell stabilizer. It is used in allergic conjunctivitis by interfering w/ chemokine-induced migration of eosinophils into inflamed conjunctiva. Onset: W/in min (ophth). Pharmacokinetics: Absorption: Completely absorbed from the GI tract (oral). Minimally absorbed (ophth). Bioavailablity: Approx 50%. Time to peak plasma concentration: 2-4 hr. Distribution: Plasma protein binding: 75%. Enters breast milk. Metabolism: Undergoes hepatic first-pass metabolism; converted to inactive ketotifen-N-glucuronide metabolite. Excretion: Mainly via urine (60-70% as metabolites, 1% as unchanged drug). Elimination half-life: Biphasic: 3-5 hr (initial); approx 21 hr (terminal).