Meclizine

— THERAPEUTIC CATEGORIES —
  • Nausea

Meclizine Generic Name & Formulations

General Description

Meclizine HCl 12.5mg, 25mg; tabs.

Pharmacological Class

Antihistamine.

How Supplied

Contact supplier

Mechanism of Action

The precise mechanism by which meclizine exerts its therapeutic effect is unknown but is presumed to involve antagonism of the histamine H1 receptor.

Meclizine Indications

Indications

Motion sickness prophylaxis. Vertigo of vestibular origin.

Meclizine Dosage and Administration

Adult

Motion sickness: 25–50mg 1 hour prior to departure, repeated every 24 hours as needed. Vertigo: 25–100mg/day in divided doses.

Children

Not established.

Meclizine Contraindications

Not Applicable

Meclizine Boxed Warnings

Not Applicable

Meclizine Warnings/Precautions

Warnings/Precautions

Asthma. Glaucoma. GI or GU obstruction. Hepatic or renal impairment. Elderly. Pregnancy. Nursing mothers.

Warnings/Precautions

Drowsiness

  • Warn patients that drowsiness may occur. Caution against driving a car or operating dangerous machinery.

  • Avoid alcoholic beverages while taking meclizine hydrochloride.

Concurrent Medical Conditions

  • Use caution in patients with asthma, glaucoma, or enlargement of the prostate gland.

Pregnancy Considerations

Risk Summary

  • Epidemiological studies have not generally indicated a drug-associated risk of major birth defects during pregnancy.

  • However, in a published study, there has been an increased incidence of fetal malformations observed in pregnant rats.

  • The risk of major birth defects and miscarriage for the indicated population is unknown.

Nursing Mother Considerations

Risk Summary

  • Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for meclizine and any potential adverse effects on the breastfed infant from meclizine or from the underlying maternal condition.

Pediatric Considerations

Safety and efficacy in pediatric patients have not been established.

Geriatric Considerations

Use caution, usually starting at the low end of the dosing range because of the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Renal Impairment Considerations

  • Use caution in patients with renal impairment because the elderly population may have a decline in renal function with age.

  • The pharmacokinetics of meclizine has not been evaluated in patients with renal impairment.

Hepatic Impairment Considerations

  • Use caution in patients with hepatic impairment.

  • Hepatic impairment may result in increased systemic exposure of meclizine.

  • The pharmacokinetics of meclizine has not been evaluated in patients with hepatic impairment.

Other Considerations for Specific Populations

Genetic CYP2D6 Polymorphism

  • Monitor for adverse reactions and clinical effect in patients with CYP2D6 polymorphism.

Meclizine Pharmacokinetics

Absorption

Maximum plasma concentrations reached at a median Tmax value of 3 hours post-dose (range: 1.5 to 6 hours).

Metabolism

Hepatic (CYP2D6).

Elimination

Renal. Half-life: 5-6 hours.

Meclizine Interactions

Interactions

Alcohol, tranquilizers, sedative-hypnotics potentiate CNS depression. May be potentiated by CYP2D6 inhibitors.

Meclizine Adverse Reactions

Adverse Reactions

Anaphylactic reaction, drowsiness, dry mouth, headache, fatigue, vomiting; rare: blurred vision.

Meclizine Clinical Trials

See Literature

Meclizine Note

Notes

Formerly known under the brand name Antivert.

Meclizine Patient Counseling

Patient Counseling

Administration Instructions

  • Swallow whole.

Adverse Reactions

  • May cause anaphylactic reaction, drowsiness, dry mouth, headache, fatigue, vomiting, and, on rare occasions, blurred vision.

  • May impair the ability to operate machinery or vehicles.

Concomitant Drug Interactions

  • Advise patients on medications that should not be taken with meclizine or medications that may need increased monitoring.

  • Advise patients that alcohol may increase adverse reactions.

Concurrent Medical Conditions

  • Notify healthcare provider regarding all medical conditions.