• Basic Info
• Top Questions
• Clinical Info

Uses

Motion Sickness

Self-medication for prevention and treatment of nausea, vomiting, and/or dizziness associated with motion sickness.

Vertigo

Symptomatic management of vertigo associated with diseases affecting the vestibular system (e.g., labyrinthitis, Ménière’s disease).

Other Uses

Use in allergic states not evaluated.

Dosage and Administration

Administration

Oral Administration

For prevention of motion sickness, administer orally 1 hour before exposure to motion; may repeat every 24 hours for duration of journey.

Dosage

Available as meclizine hydrochloride; dosage expressed in terms of meclizine.

Pediatric Patients

Motion Sickness

Oral

For self-medication in children ≥12 years of age, 25–50 mg once daily or as directed by clinician.

Adults

Motion Sickness

Oral

For self-medication, 25–50 mg once daily or as directed by clinician.

Vertigo

Oral

25–100 mg daily, administered in divided doses, depending on clinical response.

Cautions

Contraindications

• Known hypersensitivity to meclizine.

Warnings/Precautions

Warnings

CNS Effects

Possible drowsiness.

Possible additive CNS depression with other CNS depressants. (See Specific Drugs under Interactions.)

Anticholinergic Effects

Due to potential anticholinergic activity, use with caution in patients with breathing problems (e.g., asthma, emphysema, chronic bronchitis), angle-closure glaucoma, or prostatic hypertrophy.

Sensitivity Reactions

Tartrazine Sensitivity

Some formulations contain tartrazine dye (FD&C; yellow No. 5), which may cause allergic reactions (i.e., bronchial asthma) in susceptible individuals. Incidence of tartrazine sensitivity is low, but it frequently occurs in patients who have aspirin hypersensitivity.

Specific Populations

Pregnancy

Category B.

Lactation

Antihistamines may inhibit lactation and small amounts appear to be distributed into milk. Due to potential for serious adverse effects (e.g., CNS effects) in nursing infants, discontinue nursing or the drug.

Pediatric Use

Safety and efficacy not established in children <12 years of age.

Common Adverse Effects

Drowsiness, fatigue, dry mouth.

Interactions

Specific Drugs

Pharmacokinetics

Absorption

Onset

About 1 hour.

Duration

Effects persist for 8–24 hours following a single oral dose.

Distribution

Extent

Distributed throughout most body tissues; crosses placenta.

Elimination

Metabolism

Metabolic fate in humans is unknown. In rats, metabolized (probably in the liver) to norchlorcyclizine.

Elimination Route

Excreted in feces as unchanged drug and in urine as norchlorcyclizine.

Half-life

6 hours.

Stability

Storage

Oral

Capsules and Tablets

Tight, light-resistant container at 15–30°C.

Actions

• Exhibits CNS depressant, anticholinergic, antiemetic, antispasmodic, and local anesthetic effects in addition to antihistaminic activity.
• Depresses labyrinth excitability and conduction in vestibular-cerebellar pathways.
• Antiemetic and antimotion-sickness actions result, at least in part, from central anticholinergic and CNS depressant properties.

Advice to Patients

• Risk of drowsiness; use caution when driving or operating machinery.
• Importance of avoiding alcohol during therapy.
• Importance of patients informing clinicians of existing or contemplated therapy, including prescription and OTC drugs, as well as any concomitant illnesses.
• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
• Importance of informing patients of other important precautionary information. (See Cautions.)