Antiparasitic

Mepron (atovaquone)

An approved treatment for Babesiosis.

FDA Approved (1992)by GlaxoSmithKline
Preclinical
Phase 1
Phase 2
Phase 3
Approved
1992
Drug facts

The same compound appears under different names depending on the context. Here is how to identify Atovaquone wherever you encounter it, plus the key facts at a glance.

Generic name
Atovaquone
Brand name
Mepron
Drug class
Antiparasitic
Manufacturer
GlaxoSmithKline
How it's taken
For babesiosis, atovaquone is given as an oral suspension (750 mg twice daily) paired with azithromycin for 7 to 10 days.

An antiparasitic drug that is the backbone of standard babesiosis treatment. Typically combined with azithromycin as the first-line regimen for mild to moderate disease.

How Atovaquone works

Atovaquone blocks the cytochrome bc1 complex in the mitochondria of Babesia parasites. Without this enzyme complex, the parasite cannot produce the energy it needs to survive and reproduce inside red blood cells. The drug is structurally similar to coenzyme Q, which allows it to compete for the same binding site in the parasite's electron transport chain.

Mechanism: Mitochondrial electron transport chain inhibitor targeting the cytochrome bc1 complex

Side effects and safety

What patients report

The oral suspension can cause nausea, diarrhea, headache, rash, and elevated liver enzymes. Serious liver problems, including fatal liver failure, have been reported, as have severe skin reactions such as Stevens-Johnson syndrome and DRESS, which can be life-threatening. Get medical help right away for a spreading rash, blisters, peeling skin, or yellowing of the skin or eyes. It is a bright yellow liquid with a taste that some patients find unpleasant. Taking it with fatty food significantly improves absorption and is strongly recommended.

This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.

Taking Atovaquone

For babesiosis, atovaquone is given as an oral suspension (750 mg twice daily) paired with azithromycin for 7 to 10 days. Immunocompromised patients or those with severe disease may require longer courses. Must be taken with food to ensure adequate absorption.

Availability and cost

Generic available

Generic versions may be available at a lower cost. Ask your pharmacist.

Help paying for Mepron

Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.

Your insurance
From the drugmaker
Mepron (Atovaquone)
GSK Patient Assistance Program
  • Free medicine program

    Free MEPRON for uninsured US or Puerto Rico residents with no prescription coverage who meet household income limits.

    For: no insurance · source
  • Free medicine program

    Free MEPRON for Medicare Part D patients who meet income limits and have spent $600 on prescriptions this calendar year.

    For: Medicare · source

Good to know: Run by the GSK Patient Access Programs Foundation, a separate nonprofit. Covers the GSK brand (MEPRON) only, not generic versions. Income limits apply (48 states/DC: $47,880 for 1 person, $99,000 for 4). GSK's copay and coupon program lists do not include MEPRON. Generic atovaquone is widely available.

Checked on the drugmaker's official pages on September 24, 2026. Programs change; confirm with the program before you rely on it.

More ways to get help paying for treatment →

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Common questions about Atovaquone

▸What is Atovaquone (Mepron)?

An antiparasitic drug that is the backbone of standard babesiosis treatment. Typically combined with azithromycin as the first-line regimen for mild to moderate disease.

▸How does Atovaquone work?

Atovaquone blocks the cytochrome bc1 complex in the mitochondria of Babesia parasites. Without this enzyme complex, the parasite cannot produce the energy it needs to survive and reproduce inside red blood cells. The drug is structurally similar to coenzyme Q, which allows it to compete for the same binding site in the parasite's electron transport chain.

▸What are the side effects of Atovaquone?

The oral suspension can cause nausea, diarrhea, headache, rash, and elevated liver enzymes. Serious liver problems, including fatal liver failure, have been reported, as have severe skin reactions such as Stevens-Johnson syndrome and DRESS, which can be life-threatening. Get medical help right away for a spreading rash, blisters, peeling skin, or yellowing of the skin or eyes. It is a bright yellow liquid with a taste that some patients find unpleasant. Taking it with fatty food significantly improves absorption and is strongly recommended.

▸How is Atovaquone taken?

For babesiosis, atovaquone is given as an oral suspension (750 mg twice daily) paired with azithromycin for 7 to 10 days. Immunocompromised patients or those with severe disease may require longer courses. Must be taken with food to ensure adequate absorption.

▸Is Atovaquone FDA approved?

Yes, Atovaquone (Mepron) is FDA approved (1992) for the treatment of Babesiosis.

This page is for informational purposes only and does not constitute medical advice. Drug information is sourced from public databases and peer-reviewed literature and may not reflect the most recent updates. Always discuss treatment options with your healthcare provider. Last reviewed: September 2026.

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