Meclizine

INTRODUCTION

Indications

Management/prevention of Motion sickness, Vertigo.

Action

Has central anticholinergic, CNS depressant, and antihistaminic properties. Decreases excitability of the middle ear labyrinth and depresses conduction in middle ear vestibular-cerebellar pathways. Therapeutic Effects: Decreased motion sickness. Decreased vertigo from vestibular pathology.

Adverse Reactions/Side Effects

CNS: drowsiness, fatigue. EENT: blurred vision. GI: dry mouth.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor any improvements in symptoms (nausea, vomiting, dizziness, vertigo) to help document the effects of this drug.

Interventions

• Guard against falls and trauma (hip fractures, head injury, and so forth). Implement fall prevention strategies, especially in older adults or if balance is impaired (See Appendix E).

• In patients with chronic vertigo, implement therapeutic exercise and vestibular training activities to help reduce symptoms.

Patient/Client-Related Instruction

• Advise patient about the risk of daytime drowsiness and decreased attention and mental focus. These problems can be severe in certain people. Use care if driving or in other activities that require quick reactions and strong concentration.

• Advise patient to avoid alcohol and other CNS depressants because of the increased risk of sedation and adverse effects.

• Instruct patient to report other troublesome side effects including severe or prolonged fatigue, dry mouth, or blurred vision.

Pharmacokinetics

Absorption: Absorbed after oral administration.

Distribution: Unknown.

Metabolism and Excretion: Unknown.

Half-life: 6 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Pregnancy.

Use Cautiously in: Prostatic hyperplasia; Angleclosure glaucoma; Geriatric (increased sensitivity; increased risk of adverse reactions); Children or lactation (safety not established).

Interactions

Drug-Drug: Additive CNS depression with other CNS depressants, including alcohol, other antihistamines, opioid analgesics, and sedative/hypnotics. Additive anticholinergic effects with other drugs possessing anticholinergic properties, including some antihistamines, antidepressants, atropine, haloperidol, phenothiazines, quinidine, and disopyramide.

Route/Dosage

PO (Adults): Motion sickness—25–50 mg 1 hr before exposure; may repeat in 24 hr; vertigo—25–100 mg/day in divided doses.

Availability

Tablets: 12.5 mg, 25 mg Rx, OTC, 50 mg. Chewable tablets: 25 mg Rx, OTC. Capsules: 15 mg OTC, 25 mg, 30 mg OTC.