meclizine (Antivert, Bonine, Meni D, meclozine, Dramamine Less Drowsy Formula, VertiCalm)
Classes: Antiemetic Agents; Antiemetics, Antihistamine
Dosing and uses of Antivert, Bonine (meclizine)
Adult dosage forms and strengths
tablet
- 12.5mg
- 25mg
- 32mg
tablet, chewable
- 25mg
Motion Sickness
12.5-50 mg PO given 1 hour before travel and then every 24 hr PRn
Vertigo
25-100 mg/day PO in single daily dose or divided q6-12hr
Pediatric dosage forms and strengths
tablet
- 12.5mg
- 25mg
- 32mg
- 50mg
tablet, chewable
- 25mg
Motion Sickness
<12 years: Safety and efficacy not established
>12 years: 12.5-50 mg PO given 1 hour before travel and then daily PRn
Vertigo
<12 years: Safety and efficacy not established
>12 years: 25-100 mg/day PO in single daily dose or divided q6-12hr
Antivert, Bonine (meclizine) adverse (side) effects
Frequency not defined
Drowsiness
Thickening of bronchial secretions
Acute glaucoma attack
Blurred vision (rare)
Constipation
Fatigue
Vomiting
Xerostomia
Headache
Dry mouth
Urinary retention
Warnings
Contraindications
Hypersensitivity
Cautions
Use cautioin in obstructive genitourinary tract disease, asthma, pyloric or duodenal obstruction, prostatic hyperplasia, narrow angle glaucoma
Hepatic impairment may increase meclizine systemic exposure
Renal impairment may increase meclizine or metabolite accumulation
May impair physical or mental abilities; use caution when operating heavy machinery or performing tasks which require mental alertness
Pregnancy and lactation
Pregnancy category: B
Lactation: Not known if excreted in milk; use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Antivert, Bonine (meclizine)
Mechanism of action
Antihistamine with activity against nebulized histamine; blocks vasodepressor response to histamine, with slight blocking action against acetylcholine
Absorption
Onset: 30-60 min
Duration: 12-24 hr
Peak plasma time: 3 hr
Distribution
Vd: 7 L/kg
Metabolism
In vitro study found CYP2D6 the dominant metabolic enzyme
Elimination
Half-life: 5 hr
Excretion: Urine, feces
Pharmacogenomics
Genetic polymorphism of CYP2D6 that results in extensive-, poor-, intermediate- and ultrarapid metabolizer phenotypes could contribute to large interindividual variability in meclizine exposure