Classifications: antiprotozoal;
Therapeutic: antiprotozoal

Prototype: Metronidazole
Pregnancy Category: C


750 mg/5 mL suspension


Atovaquone is an antiprotozoal with antipneumocystic activity, including Pneumocystis carinii (PCP) and the Plasmodium species. The site of action in PCP is linked to inhibition of the electron transport system in the mitochondria. This results in the inhibition of nucleic acid and ATP synthesis.

Therapeutic Effect

Effective against P. carinii and the Plasmodium species, as well as other protozoans.


Second-line oral therapy of mild to moderate P. carinii pneumonia (PCP) in immunocompromised patients intolerant of cotrimoxazole.

Unlabeled Uses

May be effective in the treatment of cerebral toxoplasmosis.


History of potential life-threatening allergies to atovaquone.

Cautious Use

Severe PCP, concurrent pulmonary diseases, older adults, pregnancy (category C), or lactation; impaired hepatic function; neonates and infants.

Route & Dosage

Mild to Moderate Pneumocystis carinii Pneumonia (PCP)
Adult: PO 750 mg (5 mL) suspension b.i.d. for 21 d


  • Give with meals, because food significantly enhances absorption.
  • Store at room temperature 15°–30° C (59°–86° F) unless otherwise directed by the manufacturer.

Adverse Effects (≥1%)

Body as a Whole: Fever. CV: Hypotension. CNS: Headache, insomnia, dizziness, strange or vivid dreams, anxiety, depression. Hematologic: Anemia, neutropenia. Metabolic: Hyponatremia, hypoglycemia. GI: Nausea, diarrhea, vomiting, abdominal pain, anorexia, dyspepsia, oral candidiasis, oral ulcers. Skin: Rash, pruritus, erythema multiforme. Respiratory: Cough, sinusitis.

Diagnostic Test Interference

May cause increase in amylase and other liver function tests.


Drug: Zidovudine may increase risk of bone marrow toxicity. Food: Oral absorption is increased 3- to 4-fold when administered with food, especially with fatty foods.


Absorption: Poor, absorption improved when taken with a fatty meal. Duration: 6–23 wk after a 3-wk course of therapy. Distribution: Penetrates poorly into cerebrospinal fluid; >99.9% protein bound. Metabolism: Not metabolized. Elimination: >94% in feces over 21 d (enterohepatically cycled). Half-Life: 2–3 d.

Nursing Implications

Assessment & Drug Effects

  • Assess for therapeutic failure in patients with GI disorders that may limit absorption of drug.
  • Lab tests: Monitor CBC with differential, blood glucose, serum sodium, creatinine, BUN, and serum amylase periodically. Report abnormal elevations in these values; drug may need to be discontinued.

Patient & Family Education

  • Note: It is necessary to take this drug exactly as prescribed because it is slowly eliminated from the body.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2022 Last Updated On: 11/25/2022 (0)
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