Meclizine Hydrochloride

Generic Details

Generic Name

Meclizine Hydrochloride

Other Names

  • Meclizine HCl
  • Antivert
  • Bonine
  • Dramamine Less Drowsy

Drug Class

  • Antiemetic
  • Antihistamine

Chemical Formula

C25H27ClN2

Molecular Weight

390.95 g/mol

Mechanism of Action

  • Antagonist at the H1-receptor site
  • Antagonist at the muscarinic acetylcholine receptors

Indications

  • Motion sickness
  • Vertigo
  • Nausea/vomiting associated with inner ear disorders

Common Dosage Forms

  • Tablet
  • Chewable tablet
  • Oral solution

Typical Dosage

  • 25-50 mg every 24 hours as needed

Pediatric Dosage

  • Children 12 years and older: Follow adult dosing
  • Children under 12 years: Consult a healthcare provider

Geriatric Dosage

  • Lower initial dosages may be required due to age-related decrease in liver and kidney function

Side Effects

  • Drowsiness
  • Dry mouth
  • Blurred vision
  • Constipation
  • Dizziness

Contraindications

  • Hypersensitivity to meclizine or any component of the formulation
  • Narrow-angle glaucoma

Pregnancy Category

  • Category B - No evidence of risk in humans

Lactation Safety

  • Limited data available; caution advised

Drug Interactions

  • May enhance the sedative effects of alcohol and other CNS depressants

Overdose Symptoms

  • Extreme drowsiness
  • Seizures
  • Cardiac arrest

Antidote for Overdose

  • There is no specific antidote; treatment is supportive and symptomatic

Storage Conditions

  • Store at room temperature away from moisture and heat

Pharmacokinetics

  • Absorption: Rapidly absorbed from the gastrointestinal tract
  • Distribution: Crosses the blood-brain barrier and placenta; excreted in breast milk
  • Metabolism: Metabolized in the liver via CYP2D6 and CYP3A4
  • Excretion: Primarily eliminated in the urine

Precautions

  • Use caution when operating machinery or driving due to potential drowsiness
  • Avoid alcohol consumption while taking meclizine

Warnings

  • Use with caution in the elderly due to increased risk of anticholinergic effects

Others

  • Meclizine may also be used off-label for the prevention of migraines and as an adjunct treatment for anxiety disorders.