indication

For the prevention and treatment of nausea, vomiting, or dizziness associated with motion sickness.

pharmacology

Meclizine, a piperazine-derivative H₁-receptor antagonist similar to buclizine, cyclizine, and hydroxyzine, is used as an antivertigo/antiemetic agent. Meclizine is used in the management of nausea, vomiting, and dizziness associated with motion sickness and vertigo in diseases affecting the vestibular apparatus.

mechanism of action

Along with its actions as an antagonist at H₁-receptors, meclizine also possesses anticholinergic, central nervous system depressant, and local anesthetic effects. Meclizine depresses labyrinth excitability and vestibular stimulation and may affect the medullary chemoreceptor trigger zone.

toxicity

Symptoms of overdose include drowsiness and anticholinergic effects. LD₅₀=mg/kg (orally in rat).

biotransformation

Hepatic

absorption

Well absorbed

half life

6 hours

drug interactions

Donepezil: Possible antagonism of action

Galantamine: Possible antagonism of action

Rivastigmine: Possible antagonism of action

Tacrine: The therapeutic effects of the central acetylcholinesterase inhibitor, Tacrine, and/or the anticholinergic, Meclizine, may be reduced due to antagonism. The interaction may be beneficial when the anticholinergic action is a side effect. Monitor for decreased efficacy of both agents.

Trimethobenzamide: Trimethobenzamide and Meclizine, two anticholinergics, may cause additive anticholinergic effects and enhance their adverse/toxic effects. Monitor for enhanced anticholinergic effects.

Triprolidine: Triprolidine and Meclizine, two anticholinergics, may cause additive anticholinergic effects and enhance their adverse/toxic effects. Additive CNS depressant effects may also occur. Monitor for enhanced anticholinergic and CNS depressant effects.

Trospium: Trospium and Meclizine, two anticholinergics, may cause additive anticholinergic effects and enhanced adverse/toxic effects. Monitor for enhanced anticholinergic effects.