Meclizine

 Action Acts on CNS to decrease vestibular stimulation and depress labyrinthine activity.

 Indications Prevention and treatment of nausea, vomiting and dizziness of motion sickness; possibly effective treatment for vertigo of vestibular dysfunction origin.

 Contraindications Hypersensitivity to cyclizine; asthma; glaucoma; emphysema; chronic pulmonary disease; shortness of breath; difficulty breathing; urinary retention caused by enlarged prostate.

 Route/Dosage

Motion Sickness

ADULTS: PO 25–50 mg 1 hr before travel; may repeat q 24 hr during travel.

Vertigo

ADULTS: PO 25–100 mg/day in divided doses.

 Interactions

Alcohol, CNS depressants: Additive CNS effects.

 Lab Test Interferences False-negative result in allergy skin testing.

 Adverse Reactions

CV: Hypotension; tachycardia; palpitations. CNS: Drowsiness; excitation; nervousness; restlessness; insomnia; euphoria; ertigo; hallucinations. DERM: Rash; urticaria. EENT: Dry nose and throat; visual disturbances; tinnitus. GI: Nausea; vomiting; dry mouth; diarrhea; constipation; anorexia. GU: Urinary frequency; urinary retention; difficulty urinating.

 Precautions

Pregnancy: Category B. Lactation: Undetermined. Children: Safety and efficacy not established. Not recommended in children < 2 yr.

 Administration/Storage

• Tablets may be chewed, swallowed whole or allowed to dissolve in water.
• Store at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note glaucoma and prostatic hypertrophy.
• Monitor for side effects, especially sedation, hypotension, tachycardia and urinary retention.
• Implement safety precautions (eg, keep bed in low position and instruct patient to call for assistance when rising) if patient is experiencing sedation or vertigo.

 Patient/Family Education

• When given for motion sickness, inform patient that first dose should be taken 1 hr before exposure to motion.
• Instruct patient to take sips of water frequently, suck on ice chips or sugarless hard candy or chew sugarless gum if dry mouth occurs.
• Explain that high-fiber diet and drinking plenty of fluids may help to prevent constipation, which is common side effect.
• Instruct patient to report these symptoms to physician: sedation, dizziness, palpitations, difficulty urinating or urinary retention.
• Instruct patient to notify physician if vomiting increases or becomes severe.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
• Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
• Advise patient not to take otc medications or other prescription medications without consulting physician.