Atovaquone

By Rania Gollakner, BS, DVM, MPH

close up view of tick on a dog's muzzleWhat is atovaquone?

Atovaquone (brand name Mepron®, Malanil®, or Wellvone®) is a drug used to treat infections caused by protozoa (single-celled organisms that cause disease). It is often combined with other drugs to treat specific infections.

In cats, it is used off-label in combination with azithromycin to treat cytauxzoonosis. In dogs, it is used off-label in combination with azithromycin to treat Babesia. It may be prescribed to treat other infections in dogs such as pneumocystosis.

Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully, as their directions may be significantly different from those on the label.

How is atovaquone given?

Atovaquone comes as a liquid suspension. Before using, shake the bottle gently. To help with the absorption of this drug, give it with food that is high in fat. Your veterinarian can recommend a canned pet food to give with the medication. Measure the medication carefully. Because the liquid is thick, allow the medication to sit in the syringe so that air bubbles can settle out and be eliminated to ensure proper dosage.

"Because the liquid is thick, allow the medication to sit in the syringe so that air bubbles can settle out and be eliminated to ensure proper dosage."

This medication can take up to a few weeks before full effects are noted, but gradual improvements are usually appreciable.

What if I miss giving my pet a dose of the medication?

If you miss giving your pet a dose, give the next dose as soon as you remember, but if it is close to the next scheduled dose when you remember, skip the missed dose and give it at the next scheduled time. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Side effects from atovaquone have not been reported although data are limited in animals. However, if your pet experiences persistent vomiting, diarrhea, or skin rashes, notify your veterinarian. Any side effects that you observe should be reported to your veterinarian.

This long-acting medication may last up to six weeks and may last longer in pets with kidney or liver disease.

Are there any risk factors for this medication?

Atovaquone should be avoided in pregnant females or in any patients that are allergic to the medication. Use caution in animals with malabsorption syndromes or those that cannot take the medication with food.

Are there any drug interactions I should be aware of?

No drug interactions have been established with this drug. Certain antibiotics and anti-nausea drugs can reduce the effectiveness of atovaquone. Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

"Certain antibiotics and anti-nausea drugs can reduce the effectiveness of atovaquone."

Is there any monitoring that needs to be done with this medication?

No specific monitoring is necessary. Your veterinarian may monitor for side effects and for clinical efficacy. Blood work during therapy may also be recommended.

How do I store atovaquone?

Store atovaquone at room temperature (15°-25°C or 59°-77°F), in a tight container, and protected from light. Do not freeze this medication.

What should I do in case of an 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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