Antiparasitic / Antimalarial

Malarone (atovaquone + proguanil)

An approved treatment for Babesiosis.

FDA Approved (2000)by GlaxoSmithKline
Preclinical
Phase 1
Phase 2
Phase 3
Approved
2000
Drug facts

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

Generic name
Atovaquone + Proguanil
Brand name
Malarone
Drug class
Antiparasitic / Antimalarial
Manufacturer
GlaxoSmithKline
How it's taken
Taken orally as a fixed-dose tablet.

An antimalarial combination that is not a standard babesiosis treatment. The preferred babesiosis treatment is atovaquone plus azithromycin. Some experts use atovaquone-proguanil plus azithromycin as an alternative for people with weakened immune systems whose infection keeps coming back. Atovaquone disrupts parasite energy production while proguanil inhibits folate synthesis.

How Atovaquone + Proguanil works

Atovaquone blocks the mitochondrial electron transport chain in Babesia parasites, cutting off their energy supply. Proguanil inhibits dihydrofolate reductase, disrupting the parasite's ability to synthesize DNA. Together they attack two separate metabolic pathways, reducing the chance of resistance.

Mechanism: Mitochondrial electron transport chain inhibitor (atovaquone) combined with dihydrofolate reductase inhibitor (proguanil)

Side effects and safety

What patients report

Common side effects include nausea, vomiting, abdominal pain, diarrhea, and headache. Elevated liver enzymes have been reported. Serious but rare reactions include severe skin reactions such as Stevens-Johnson syndrome, which can be life-threatening or fatal, and liver problems ranging from hepatitis to liver failure that needed a liver transplant. The label also warns that vomiting or diarrhea can lower how much atovaquone the body absorbs, so the medicine may work less well. People with severe kidney problems should not take it to prevent malaria, and should use it for treatment only with caution.

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 + Proguanil

Taken orally as a fixed-dose tablet. There is no standard babesiosis dose; when experts use it for relapsing babesiosis it is given with azithromycin. Should be taken with food or a milky drink to improve absorption. The standard babesiosis regimen pairs atovaquone (750 mg twice daily) with azithromycin rather than proguanil, though the Malarone formulation is sometimes used.

Availability and cost

Generic available

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

Help paying for Malarone

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
Malarone (Atovaquone + Proguanil)
GSK Patient Assistance Program
  • Free medicine program

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

    For: no insurance · source
  • Free medicine program

    Free MALARONE 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 (MALARONE) 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 MALARONE. Generic atovaquone-proguanil 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 + Proguanil

▸What is Atovaquone + Proguanil (Malarone)?

An antimalarial combination that is not a standard babesiosis treatment. The preferred babesiosis treatment is atovaquone plus azithromycin. Some experts use atovaquone-proguanil plus azithromycin as an alternative for people with weakened immune systems whose infection keeps coming back. Atovaquone disrupts parasite energy production while proguanil inhibits folate synthesis.

▸How does Atovaquone + Proguanil work?

Atovaquone blocks the mitochondrial electron transport chain in Babesia parasites, cutting off their energy supply. Proguanil inhibits dihydrofolate reductase, disrupting the parasite's ability to synthesize DNA. Together they attack two separate metabolic pathways, reducing the chance of resistance.

▸What are the side effects of Atovaquone + Proguanil?

Common side effects include nausea, vomiting, abdominal pain, diarrhea, and headache. Elevated liver enzymes have been reported. Serious but rare reactions include severe skin reactions such as Stevens-Johnson syndrome, which can be life-threatening or fatal, and liver problems ranging from hepatitis to liver failure that needed a liver transplant. The label also warns that vomiting or diarrhea can lower how much atovaquone the body absorbs, so the medicine may work less well. People with severe kidney problems should not take it to prevent malaria, and should use it for treatment only with caution.

▸How is Atovaquone + Proguanil taken?

Taken orally as a fixed-dose tablet. There is no standard babesiosis dose; when experts use it for relapsing babesiosis it is given with azithromycin. Should be taken with food or a milky drink to improve absorption. The standard babesiosis regimen pairs atovaquone (750 mg twice daily) with azithromycin rather than proguanil, though the Malarone formulation is sometimes used.

▸Is Atovaquone + Proguanil FDA approved?

Yes, Atovaquone + Proguanil (Malarone) is FDA approved (2000) 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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