Meclizine

Indications

Meclizine is used to prevent and treat nausea, vomiting and dizziness caused by motion sickness (travel sickness), and to relieve vertigo (a spinning feeling) from inner ear problems. Doctors may also use it, sometimes together with Pyridoxine, for nausea and vomiting of pregnancy.

How It Works

It is an antihistamine that calms the balance centre of the inner ear and the vomiting centre of the brain, so it reduces nausea and the spinning feeling.

Dosage and Administration

Adults, motion sickness: 25 to 50 mg about 1 hour before travel, repeated every 24 hours if needed. Vertigo: usually 25 to 100 mg a day in divided doses, as advised by the doctor. Nausea of pregnancy: only as prescribed. Children under 12: only on a doctor's advice. It can be taken with or without food.

Interactions

• Alcohol, sleeping pills, sedatives, opioid painkillers and other antihistamines increase drowsiness.
• Medicines with anticholinergic effects (such as Amitriptyline and some bladder and Parkinson's medicines) can add to dry mouth, constipation, blurred vision and difficulty passing urine.

Contraindications

Allergy to meclizine or similar antihistamines.

Side Effects

Common: drowsiness, tiredness, dry mouth, headache and, less often, blurred vision or vomiting.

Get urgent medical help for a serious allergic reaction (rash, swelling of the face or throat, difficulty breathing), a fast or irregular heartbeat, confusion or hallucinations, or being unable to pass urine.

Pregnancy and Lactation

Meclizine has been used for many years for nausea of pregnancy and is not known to harm the baby, but use it in pregnancy only on a doctor's advice. It may pass into breast milk and could reduce milk supply or make the baby sleepy; ask a doctor before using it while breastfeeding.

Precautions and Warnings

• It can make you drowsy; do not drive or operate machines until you know how it affects you, and avoid alcohol.
• Take care if you have asthma, glaucoma, an enlarged prostate or difficulty passing urine, or liver or kidney disease.
• Older adults are more likely to feel confused or drowsy.
• See a doctor if vertigo is new, severe, or comes with weakness, numbness, slurred speech, hearing loss or a severe headache.

Overdose

Overdose can cause severe drowsiness, confusion, fast heartbeat and dry, flushed skin; in children it may cause excitement, hallucinations or seizures. Get emergency medical help.

Therapeutic Class

Antihistamine (H1 blocker) used as an antiemetic and anti-vertigo medicine.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.