MECLIZINE HYDROCHLORIDE

(mek'li-zeen)

Antivert, Antrizine, Bonamine

, Bonine, Dizmiss, RuVert-M
Classifications: antihistamine; h₁-receptor antagonist; anti-vertigo agent;
Therapeutic: antihistamine, h₁-receptor antagonist, antivertigo
Pregnancy Category: B

Availability

12.5 mg, 25 mg, 50 mg tablets; 25 mg, 30 mg capsules

Action

Long-acting antihistamine, with marked effect in blocking histamine-induced vasopressive response but only slight anticholinergic action. Marked depressant action on labyrinthine excitability and on conduction in vestibular-cerebellar pathways.

Therapeutic Effect

Exhibits antivertigo, and antiemetic effects.

Uses

Management of nausea, vomiting, and dizziness associated with motion sickness and in vertigo associated with diseases affecting vestibular system.

Contraindications

Hypersensitivity to meclizine; GI obstruction, ileus.

Cautious Use

Angle-closure glaucoma, older adults, asthma, prostatic hypertrophy, pregnancy (category B), lactation. Safety in children less than 12 y is not established.

Route & Dosage

Motion Sickness
Adult: PO 25–50 mg 1 h before travel, may repeat q24h if necessary for duration of journey

Vertigo
Adult: PO 25–100 mg/d in divided doses

Administration

Oral

Give without regard to meals.
Ensure that chewable tablets are chewed or crushed before being swallowed with a liquid.

Adverse Effects (≥1%)

CNS: Drowsiness. GI: Dry mouth. Special Senses: Blurred vision. Body as a Whole: Fatigue.

Interactions

Drug: Alcohol, cns depressants may potentiate sedative effects of meclizine.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Onset: 1 h. Duration: 8–24 h. Distribution: Crosses placenta. Elimination: Primarily in feces. Half-Life: 6 h.

Nursing Implications

Assessment & Drug Effects

Supervision of ambulation, particularly with the older adult, since drug may cause drowsiness.
Assess effectiveness of drug and inform physician when prescribed for vertigo; dosage adjustment may be required.

Patient & Family Education

Do not drive or engage in potentially hazardous activities until response to drug is known.
Be aware that sedative action may add to that of alcohol, barbiturates, narcotic analgesics, or other CNS depressants.
Take 1 h before departure when prescribed for motion sickness.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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