Meclizine (Antivert) | Medication Reference

Bedside Snapshot

Core Use: Oral H1 antihistamine with anticholinergic activity used primarily for vertigo and motion sickness-related nausea
Typical ED Dose: 25–50 mg PO for vertigo with nausea, often alongside vestibular maneuvers when BPPV is suspected
Onset/Duration: Onset within 1 hour; peak effect 1–4 hours; effects persist 5–6 hours but can be prolonged in elderly patients
Key Dangers: Sedation, dry mouth, blurred vision, urinary retention, and confusion particularly in older adults (Beers list medication); increased fall risk
Special Notes: Best suited for stable patients with suspected peripheral vertigo; not for active vomiting requiring parenteral therapy; avoid prolonged use in vestibular neuritis when vestibular rehabilitation is planned

Brand & Generic Names

Generic Name: Meclizine hydrochloride
Brand Names: Antivert, Bonine, Dramamine Less Drowsy, generics

Medication Class

First-generation antihistamine (H1 antagonist) with anticholinergic and antiemetic properties; antivertigo agent

Pharmacology

Mechanism of Action:

Blocks central and peripheral H1 histamine receptors, reducing vestibular stimulation and suppressing labyrinthine function
Anticholinergic (antimuscarinic) effects in vestibular pathways help reduce motion-induced nausea and vomiting
Central sedative properties may contribute to symptom relief in vertigo but also increase risk of drowsiness and cognitive impairment

Pharmacokinetics:

Absorption: Well absorbed orally; onset of action typically within 1 hour, with peak effect in 1–4 hours
Distribution: Lipophilic with good CNS penetration
Metabolism: Hepatic, primarily via CYP enzymes; subject to first-pass metabolism
Elimination: Metabolites excreted renally; elimination half-life around 5–6 hours, though sedative effects can persist longer in older or sensitive patients
Special Considerations: Dose adjustment may be warranted in hepatic impairment and in older adults due to increased sensitivity and prolonged effects

Indications

Symptomatic treatment of vertigo associated with vestibular disorders (e.g., vestibular neuritis, labyrinthitis, BPPV) once serious central causes (e.g., stroke) are excluded
Prevention and treatment of motion sickness-associated nausea, vomiting, and dizziness (often outpatient/EMS use)
Adjunct in patients with chronic vestibular disorders in conjunction with vestibular rehabilitation exercises (more outpatient than ICU)

Dosing & Administration

Available Forms:

Tablets/chewable tablets: 12.5 mg, 25 mg, 50 mg (common adult strengths)
Oral capsules in some formulations: usually 25 mg
Often available over-the-counter in lower doses/combination products; verify exact strength for dosing

Dosing Guidelines (Adult):

Indication	Dose	Frequency	Notes
Vertigo (acute symptom control)	25–50 mg PO	Every 6–8 hours as needed	Use shortest effective course; avoid prolonged suppression in vestibular neuritis if doing rehab
Motion sickness (prevention)	25–50 mg PO	Taken 1 hour before travel; may repeat q24h	Counsel on sedation; avoid driving if drowsy
Elderly or frail	12.5–25 mg PO	Every 8–12 hours as needed	Increased risk of confusion, falls, urinary retention; consider alternatives
Maximum usual daily dose (adult)	100 mg/day	Divided doses	Higher doses increase anticholinergic and sedative effects
Hepatic or renal impairment	Start low (12.5–25 mg)	Extend dosing interval	Monitor for accumulation and prolonged sedation

Contraindications

Contraindications:

Known hypersensitivity to meclizine or other piperazine-derived antihistamines
Use in neonates/infants (safety not established; avoid)
Caution approaching contraindication in patients with narrow-angle glaucoma, urinary retention/BPH, or severe asthma (due to anticholinergic effects)

Major Precautions:

Older adults: increased risk of sedation, cognitive impairment, and falls; meclizine is a Beers list medication
Use caution in patients with glaucoma, BPH/urinary retention, or severe constipation due to anticholinergic effects
CNS depression may be additive with alcohol, benzodiazepines, opioids, and other sedatives; counsel patients accordingly
May impair ability to drive or operate machinery; advise patients not to perform hazardous tasks until they know how they respond
Avoid prolonged use in vestibular neuritis when vestibular rehabilitation is planned, as chronic suppression can delay central compensation

Beers Criteria Warning: Meclizine is on the American Geriatrics Society Beers list due to high risk of anticholinergic adverse effects in older adults, including confusion, dry mouth, constipation, and increased fall risk.

Adverse Effects

Common:

Drowsiness, fatigue
Dry mouth, blurred vision
Mild constipation or urinary hesitancy
Occasional headache

Serious (less common):

Confusion, delirium, or hallucinations, especially in older adults or with high doses
Urinary retention, especially in men with BPH
Acute angle-closure glaucoma in susceptible individuals (rare)
Severe hypotension or arrhythmias when combined with other sedative or anticholinergic drugs (rare)

Special Populations

Elderly Patients:

Start with lowest dose (12.5–25 mg) and monitor closely for sedation, confusion, and fall risk
Consider non-pharmacologic alternatives when possible (vestibular rehabilitation, hydration, blood pressure management)

Hepatic Impairment:

Use with caution; start with lower doses and extend dosing intervals
Monitor for prolonged sedation and anticholinergic effects

Renal Impairment:

Dose adjustment may be needed; start low and titrate carefully
Metabolites are renally excreted; monitor for accumulation

Pregnancy:

Category B: Animal studies show no risk, but human data limited
Generally considered acceptable for severe nausea/vomiting in pregnancy when benefits outweigh risks

Lactation:

Unknown if excreted in breast milk; use with caution
May cause sedation or irritability in nursing infants

Monitoring

Clinical Monitoring:

Symptom relief: improvement in vertigo, nausea, and ability to ambulate safely
Level of sedation and mental status, particularly in older adults
Screen for urinary retention, constipation, and visual changes in at-risk patients
Reassess need for continued therapy; in vestibular disorders, encourage transition to vestibular rehab rather than chronic meclizine

Clinical Pearls

Short-Term Use Only: Meclizine is best for short-term symptom control of peripheral vertigo and motion sickness; it does not treat the underlying cause.

BPPV Management: For BPPV, medication alone is inadequate; combine with appropriate repositioning maneuvers (Epley, Semont) and patient education.

Elderly Fall Risk: In elderly patients who are dizzy and fall-prone, consider non-sedating strategies (rehab, hydration, blood pressure optimization) before reaching for meclizine.

Central Vertigo Warning: If dizziness is central or stroke-like (ataxia, dysarthria, focal deficits), do not mask symptoms with meclizine—prioritize imaging and neurologic evaluation.

Vestibular Rehabilitation: Chronic meclizine use can delay central compensation in vestibular neuritis. Encourage early transition to vestibular physical therapy exercises.

References

1. Lexicomp. (2024). Meclizine: Drug information. Wolters Kluwer.
2. Furman, J. M., & Cass, S. P. (1999). Benign paroxysmal positional vertigo. New England Journal of Medicine, 341(21), 1590–1596. https://doi.org/10.1056/NEJM199911183412107
3. Post, R. E., & Dickerson, L. M. (2010). Dizziness: A diagnostic approach. American Family Physician, 82(4), 361–368.
4. American Geriatrics Society Beers Criteria Update Expert Panel. (2023). American Geriatrics Society 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society, 71(7), 2052–2081. https://doi.org/10.1111/jgs.18372
5. Strupp, M., & Brandt, T. (2008). Diagnosis and treatment of vertigo and dizziness. Deutsches Ärzteblatt International, 105(10), 173–180. https://doi.org/10.3238/arztebl.2008.0173