Antiprotozoal / Antipneumocystis Pregnancy: eMC §4.6: No information on effects during human pregnancy. Atovaquone should not be used during pregnancy unless the benefit of treatment to the mother outweighs any possible risk to the developing foetus. Breastfeeding: it is not known whether atovaquone is excreted in human milk, therefore breast-feeding is not recommended. This presentation contains benzyl alcohol — use with caution and only if necessary in pregnant or breast-feeding patients (risk of accumulation and toxicity). (US labelling: Pregnancy Category C.)

Atovaquone

Brand names: Wellvone

Atovaquone is an antiprotozoal agent used for the treatment and prevention of Pneumocystis jirovecii pneumonia and, combined with proguanil, for malaria.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 750 mg (5 ml of 750 mg/5 ml oral suspension) twice daily

Route: Oral

Frequency: Twice a day (morning and evening), with food, for 21 days

eMC §4.2 (Atovaquone Glenmark 750 mg/5 ml oral suspension), Pneumocystis pneumonia: 'The recommended oral dose is 750 mg twice a day (1 x 5 ml morning and evening) administered with food each day for 21 days. Higher doses may be more effective in some patients.' MUST be taken with food — the SPC stresses the importance of taking the full prescribed dose with food; food, particularly high-fat food, increases bioavailability two- to three-fold. Children: UK SPC states 'Dosage in Children: Clinical efficacy has not been studied' — no paediatric dose given. Older people: no studies in the elderly; the SPC advises use in the elderly should be closely monitored. Efficacy has NOT been systematically evaluated in patients failing other PCP therapy (including co-trimoxazole), for severe PCP [(A-a)DO2 > 45 mmHg (6 kPa)], as PCP prophylaxis, or versus intravenous pentamidine; no data in non-HIV immunocompromised patients with PCP. Diarrhoea at the start of treatment is associated with significantly lower atovaquone plasma levels, higher therapy failure and lower survival — consider alternative therapy in such patients and in those who have difficulty taking it with food. This presentation contains benzyl alcohol (SPC §4.4). US labelling (Lupin, DailyMed 2021) additionally states a PCP PREVENTION regimen of 1,500 mg (10 mL) once daily with food, and the same treatment regimen of 750 mg (5 mL) twice daily with food for 21 days — the UK SPC used here does not carry a prophylaxis indication; verify against the UK SPC/local policy before using for prophylaxis.

Dose adjustments

Renal

eMC §4.2: Not specifically studied in patients with significant hepatic or renal impairment. If it is necessary to treat such patients, caution is advised and administration should be closely monitored. No numeric dose adjustment is stated. Benzyl alcohol content — use with caution in liver or kidney impairment (risk of accumulation and metabolic acidosis). US labelling §5.2: closely monitor patients with severe hepatic impairment following administration (cases of cholestatic hepatitis, elevated liver enzymes and fatal liver failure reported).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to atovaquone or to any of the excipients (eMC §4.3)
US labelling additionally: patients who develop or have a history of hypersensitivity reactions (e.g. angioedema, bronchospasm, throat tightness, urticaria) to atovaquone or any component

Side effects

Very common: nausea
Very common: rash, pruritus
Common: diarrhoea, vomiting
Common: headache, insomnia, fever
Common: anaemia, neutropenia, hyponatraemia
Common: elevated liver enzyme levels; hypersensitivity reactions including angioedema, bronchospasm and throat tightness
Not known: erythema multiforme, Stevens-Johnson Syndrome

Interactions

Rifampicin or rifabutin — concomitant administration is NOT recommended (reduces atovaquone concentrations)
Tetracycline — reduces atovaquone concentrations; monitor patients closely for loss of atovaquone efficacy
Metoclopramide — concurrent use not recommended; give another antiemetic
Efavirenz or boosted protease inhibitors — concomitant administration should be avoided whenever possible
Etoposide — atovaquone can increase levels of etoposide and its metabolite
Indinavir (US labelling) — reduces indinavir trough concentrations; use caution and monitor for loss of indinavir efficacy

Clinical monograph

How it works

It inhibits the parasite cytochrome bc1 complex, disrupting mitochondrial electron transport and pyrimidine synthesis.

Prescribing in practice

Absorption is poor and significantly increased by fatty food, so it should be taken with food to ensure efficacy.
It is an alternative in patients intolerant of co-trimoxazole for Pneumocystis pneumonia, generally in milder disease.
Plasma concentrations may be reduced by interacting drugs such as rifampicin, potentially compromising efficacy.

Monitoring

Monitor clinical response and, where relevant, ensure adequate absorption by confirming it is taken with food.

Counselling the patient

Always take with a fatty meal to help your body absorb the medicine.
Report worsening breathlessness, fever or cough.
Do not stop preventive treatment without advice.

Evidence & guidelines

Atovaquone is recommended as an alternative agent for Pneumocystis jirovecii pneumonia and, with proguanil, for malaria in current guidance.

Reference: BHIVA Guidelines on the management of opportunistic infection (2019); NICE HIV management guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways