Atovaquone is a medication that interferes with the reproduction of protozoa (single-cell organisms) that can cause disease in the body.

Atovaquone is used to treat or prevent pneumonia caused by a fungal infection called Pneumocystitis carinii (also called Pneumocystis jiroveci).

Atovaquone may also be used for other purposes not listed in this medication guide.

You should not use this medication if you are allergic to atovaquone.

Before using this medication, tell your doctor if you have liver disease, or a stomach or intestinal disorder.

Also tell your doctor if you use other medications such as rifabutin (Mycobutin), rifampin (Rifadin, Rifater, Rifamate, Rimactane), a blood thinner such as warfarin (Coumadin), or a seizure medication such as carbamazepine (Carbatrol, Tegretol), divalproex (Depakote), phenytoin (Dilantin), or valproic acid (Depakene).

Take atovaquone with a meal for best results.

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

Call your doctor at once if you have a serious side effect such as easy bruising or bleeding, fever, flu symptoms, white patches in your mouth or throat, worsening cough, wheezing, trouble breathing, a severe red or peeling skin rash, or jaundice (yellowing of the skin or eyes).

You should not use this medication if you are allergic to atovaquone.

If you have certain conditions, you may need a dose adjustment or special tests to safely take this medication. Before you take atovaquone, tell your doctor if you have:

• liver disease; or

• a stomach or intestinal disorder.

FDA pregnancy category C. It is not known whether atovaquone is harmful to an unborn baby. Before you take atovaquone, tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether atovaquone passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.