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Atovaquone Side Effects

Medically reviewed by Last updated on May 9, 2022.

For the Consumer

Applies to atovaquone: oral suspension

Side effects requiring immediate medical attention

Along with its needed effects, atovaquone may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking atovaquone:

More common

  • Cough or hoarseness
  • difficult or labored breathing
  • fever or chills
  • lower back or side pain
  • painful or difficult urination
  • tightness in the chest

Incidence not known

  • Black, tarry stools
  • bleeding gums
  • bloating
  • blood in the urine or stools
  • bluish-colored lips, fingernails, or palms
  • constipation
  • dark urine
  • dizziness or lightheadedness
  • fast heartbeat
  • headache
  • indigestion
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • light-colored stools
  • loss of appetite
  • nausea
  • noisy breathing
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pale skin
  • pinpoint red spots on the skin
  • rapid heart rate
  • sore throat
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting
  • yellow eyes or skin

Side effects not requiring immediate medical attention

Some side effects of atovaquone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Abdominal or stomach pain
  • diarrhea
  • lack or loss of strength
  • runny nose
  • skin rash
  • sneezing
  • sore mouth or tongue
  • stuffy nose
  • sweating
  • trouble sleeping
  • white patches in the mouth, tongue, or throat

Incidence not known

  • Blistering, peeling, or loosening of the skin
  • eye irritation or redness
  • itching or skin rash
  • joint or muscle pain
  • red skin lesions, often with a purple center

For Healthcare Professionals

Applies to atovaquone: oral suspension


In PCP prevention studies comparing atovaquone to inhaled pentamidine, 16% to 25% of patients discontinued atovaquone and 7% discontinued pentamidine due to adverse events. Rash (6%), diarrhea (4%), and nausea (3%) were the most common reasons for discontinuing atovaquone, while bronchospasm (2%) was the most common reason for discontinuing pentamidine. In studies comparing atovaquone to dapsone, treatment-limiting hypersensitivity reactions were more frequent in the dapsone group (16.1%) and treatment-limiting gastrointestinal side effects were more common in the atovaquone group (up to 4.1%).

In PCP treatment studies, 9% of patients discontinued atovaquone due to side effects, compared to 24% of patients receiving sulfamethoxazole-trimethoprim. The most common reason for discontinuation in both treatment groups was rash (atovaquone, 4%; sulfamethoxazole-trimethoprim, 8%). In studies comparing intravenous pentamidine and atovaquone, 63% of patients in the atovaquone group and 72% of patients in the pentamidine group reported side effects. Treatment was discontinued in 7% of the atovaquone patients and 41% of the pentamidine patients due to adverse events; the most common reasons were rash (4%) in the atovaquone group and hypoglycemia (11%) and vomiting (9%) in the pentamidine group.[Ref]


Gastrointestinal side effects are among the most common and have included nausea (up to 40%), diarrhea (up to 42%), vomiting (up to 22%), abdominal pain (up to 21%), oral monilia (up to 10%), taste perversion (3%), and constipation (3%). The incidence of side effects was higher in patients in PCP treatment studies than in prevention studies. Seven percent of patients experience anorexia and 5% of patients experience dyspepsia, although these are difficult to attribute to the drug due to the serious underlying diseases in the patients who receive atovaquone. Hyperamylasemia has been reported in 8% of patients. Pancreatitis has also been reported during postmarketing experience.[Ref]


Dermatologic side effects have included rash (up to 46%), pruritus (greater than or equal to 10%), exfoliative dermatitis, photosensitivity, and toxic epidermal necrolysis. Erythema multiforme, Stevens-Johnson syndrome, and skin desquamation have been reported during postmarketing experience in patients receiving multiple drug treatment including atovaquone.[Ref]


Hepatic side effects have included elevated ALT (greater than 5 times ULN, 6%), elevated AST (greater than 5 times ULN, 4%), elevated alkaline phosphatase (greater than 2.5 times ULN, up to 8%), and increased amylase (greater than 1.5 times ULN, up to 8%) in patients being treated for PCP. Therapy was discontinued in 2% of patients receiving atovaquone due to ALT/AST elevations, compared to 7% of patients being treated with sulfamethoxazole-trimethoprim. Hepatomegaly has also been reported. Rarely, hepatitis and at least one case of fatal liver failure have been reported during postmarketing experience.[Ref]


Hematologic side effects have included anemia (up to 6%) and neutropenia (up to 5%), but may be due to underlying disease. Methemoglobinemia and thrombocytopenia have also been reported.[Ref]


Metabolic side effects have included hyponatremia (up to 10%), hyperglycemia (9%), and hypoglycemia (1%).[Ref]


Other side effects have included fever (up to 40%), asthenia (up to 31%), flu syndrome (greater than or equal to 10%), pain (greater than or equal to 10%), infection (up to 22%), sweating (greater than or equal to 10%), and malaise, but some may be due to underlying disease. Fatigue, night sweats, and burning sensation of the tongue have also been reported.[Ref]


Respiratory side effects have included dyspnea (up to 21%), increased cough (up to 25%), rhinitis (up to 24%), sinusitis (greater than or equal to 10%), bronchospasm (up to 4%), and pneumonia.[Ref]

Nervous system

Nervous system side effects have included insomnia (up to 19%), dizziness (up to 8%), headache (up to 31%), anxiety (7%), and depression (greater than or equal to 10%).[Ref]


Musculoskeletal side effects have included myalgia (greater than or equal to 10%).[Ref]


Hypersensitivity reactions have included rash, erythema multiforme, exfoliative dermatitis, and allergic reactions (unspecified, up to 1.1%).[Ref]


Renal side effects have included elevated creatinine (1%) and elevated BUN (1%). Acute renal impairment has been reported during postmarketing experience.[Ref]


Cardiovascular side effects have included hypotension (1%).


Ocular side effects have included vortex keratopathy during postmarketing experience.[Ref]


Immunologic side effects have included hypersensitivity reactions including angioedema, bronchospasm, throat tightness, and urticaria during postmarketing experience.[Ref]


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7. "Product Information. Mepron (atovaquone)." Glaxo Wellcome (2002):

8. Dohn MN, Weinberg WG, Torres RA, Follansbee SE, Caldwell PT, Scott JD, Gathe JC, Haghighat DP, Sampson JH, Spotkov J, Der "Oral atovaquone compared with intravenous pentamidine for pneumocystis carinii pneumonia in patients with AIDS." Ann Intern Med 121 (1994): 174-80

9. Hughes WT, Lafon SW, Scott JD, Masur H "Adverse events associated with trimethoprim-sulfamethoxazole and atovaquone during the treatment of AIDS-related pneumocystis carinii pneumonia." J Infect Dis 171 (1995): 1295-301

10. Haile LG, Flaherty JF "Atovaquone: a review." Ann Pharmacother 27 (1993): 1488-94

11. Torres RA, Weinberg W, Stansell J, Leoung G, Kovacs J, Rogers M, Scott J "Atovaquone for salvage treatment and suppression of toxoplasmic encephalitis in patients with AIDS." Clin Infect Dis 24 (1997): 422-9

12. Chan C, Montaner J, Lefebvre EA, Morey G, Dohn M, McIvor RA, Scott J, Marina R, Caldwell P "Atovaquone suspension compared with aerosolized pentamidine for prevention of Pneumocystis carinii pneumonia in human immunodeficiency virus-infected subjects intolerant of trimethoprim or sulfonamides." J Infec Dis 180 (1999): 369-76

13. Falloon J, Sargent S, Piscitelli SC, Bechtel C, LaFon SW, Sadler B, Walker RE, Kovacs JA, Polis MA, Davey RT, Lane HC, Ma "Atovaquone suspension in HIV-infected volunteers: Pharmacokinetics, pharmacodynamics, and TMP-SMX interaction study." Pharmacotherapy 19 (1999): 1050-6

14. Iaccheri B, Fiore T, Papadaki T, et al. "Adverse drug reactions to treatments for ocular toxoplasmosis: A retrospective chart review." Clin Ther 30 (2008): 2069-74

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17. Dixon R, Pozniak AL, Watt HM, Rolan P, Posner J "Single-dose and steady-state pharmacokinetics of a novel microfluidized suspension of atovaquone in human immunodeficienc virus-seropositive patients." Antimicrob Agents Chemother 40 (1996): 556-60

18. ElSadr WM, Murphy RL, Yurik RM, LuskinHawk R, Cheung TW, Balfour HH, Eng R, Hooton TM, Kerkering TM, Schutz M, vanderHorst "Atovaquone compared with dapsone for the prevention of Pneumocystis carinii pneumonia in patients with HIV infection who cannot tolerate trimethoprim, sulfonamides, or both." N Engl J Med 339 (1998): 1889-95

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21. Shah GK, Cantrill HL, Holland EJ "Vortex keratopathy associated with atovaquone." Am J Ophthalmol 120 (1995): 669-71

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.