Meclizine

By Lauren R. Forsythe, PharmD, MBA, DICVP; Rania Gollakner, BS, DVM, MPH

What is meclizine?

Meclizine (brand names Antivert®, Dramamine® Less Drowsy Formula, Bonine®, Bonamine®, Postafen®, Univert®) is an antihistamine used off label to prevent and treat motion sickness and vomiting associated with it, in cats, dogs, and other small mammals.

Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is meclizine given?

  • Meclizine is given by mouth in the form of a tablet. 
  • It can be given with or without food; however, giving this medication with a treat or small meal may help prevent vomiting. 
  • If using this medication to prevent motion sickness during travel, give the medication at least 30-60 minutes prior to travel.

This medication will take effect quickly, in about 1 to 2 hours, and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then wait the recommended amount of time between doses. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Meclizine may cause the following side effects:

  • sedation or sleepiness (common)
  • dry gums and eyes
  • fast heart rate 
  • excitement instead of sleepiness, due to central nervous system stimulation
  • lack of appetite (in cats)

This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

Meclizine should NOT BE USED in pets that are allergic to it.

Meclizine should be USED WITH CAUTION in pets that:

  • have prostatic hypertrophy (enlarged prostate)
  • have bladder neck obstruction
  • have severe heart failure
  • have angle-closure glaucoma
  • have pyeloduodenal obstruction (obstruction between the stomach and small intestine)
  • are pregnant or nursing

This medication may also interfere with allergy skin testing. Discontinue this medication 3-7 days before skin testing.

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with meclizine:

  • central nervous system (CNS) depressants 
  • anticholinergic drugs

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is any monitoring needed with this medication?

  • Monitor your pet for prolonged or severe side effects while they are taking this medication. 
  • Your veterinarian may monitor your pet to be sure that the medication is working.

How do I store meclizine?

  • Store meclizine at room temperature, in a tight container.
  • Store away from light.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

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