Class: Antihistamine, Antiemetic
Dosage Forms. Tablet: 12.5 mg, 25 mg, 50 mg; Tablet, Chewable: 25 mg
Common FDA Label Indication, Dosing, and Titration.
1. Motion sickness: 25-50 mg po 1 h before departure, may repeat q24h prn
2. Vertigo: 25-100 mg po daily in 1-3 divided doses, depending on clinical response
Off-Label Uses.
1. Radiation-induced nausea and vomiting: 50 mg po 2-12 h prior to radiotherapy
MOA. Meclizine is an antihistamine that suppresses the vasodepressor response to histamine while only slightly inhibiting acetylcholine.
Drug Characteristics: Meclizine
Medication Safety Issues: Meclizine
Drug Interactions: Meclizine
Adverse Reactions: Meclizine
Efficacy Monitoring Parameters. Improvement in nausea or vertigo symptoms.
Toxicity Monitoring Parameters. Seek medical attention for signs of severe CNS toxicity.
Key Patient Counseling Points. Since drowsiness may, on occasion, occur with use of this drug, patients should be warned of this possibility and cautioned against driving a car or operating dangerous machinery. Patients should avoid alcoholic beverages while taking this drug. Due to its potential anticholinergic action, this drug should be used with caution in patients with asthma, glaucoma, or enlargement of the prostate gland.
Clinical Pearls. Meclizine is available over the counter in many different products, and by prescription. Caution should be used to avoid duplication of therapy and patients should be advised on product selection.