Atovaquone

Atovaquone Should be taken with food.

Hypersensitivity.

Patient with gastrointestinal disorders (e.g. vomiting, chronic diarrhoea) or pulmonary disease. Consider alternative therapies for patients who have gastrointestinal disorders or difficulty taking atovaquone with food, as these conditions may limit its absorption, resulting in significantly lower plasma atovaquone concentration. Evaluate patients with pulmonary disease for causes other than Pneumocystis jirovecii pneumonia (PCP) and treat as appropriate. Efficacy of atovaquone for use in patients who are failing trimethoprim-sulfamethoxazole therapy or for the treatment of severe PCP episodes has not been systematically evaluated. Significant renal and hepatic impairment. Elderly. Pregnancy and lactation.

Significant: Hypersensitivity reactions (e.g. bronchospasm, angioedema, urticaria); vomiting, diarrhoea. Rarely, increased LFTs, cholestatic hepatitis.
Blood and lymphatic system disorders: Neutropenia, anaemia.
Gastrointestinal disorders: Nausea.
General disorders and administration site conditions: Fever, flu-like symptoms.
Infections and infestations: Oral candidiasis.
Investigations: Increased serum amylase levels.
Metabolism and nutrition disorders: Hyponatraemia.
Nervous system disorders: Headache.
Psychiatric disorders: Insomnia, depression.
Respiratory, thoracic and mediastinal disorders: Cough, sinusitis, rhinitis.
Skin and subcutaneous tissue disorders: Rash, pruritus, diaphoresis.
Potentially Fatal: Rarely, liver failure.

PO: C

Obtain LFTs at baseline and during treatment. Assess the patient's food tolerance prior to oral intake. Monitor for post-dose vomiting and diarrhoea and for signs of hypersensitivity reactions.

Significantly decreased plasma concentrations with rifampicin, rifabutin, metoclopramide, efavirenz or boosted protease inhibitors, and tetracycline. Slightly decreased plasma levels with laxatives, benzodiazepines, antidiarrhoeals, opiates, cephalosporins, aciclovir, and paracetamol. May increase the serum levels of etoposide and its metabolites. May reduce the metabolism rate of zidovudine, leading to increased plasma zidovudine levels. May decrease the trough concentrations of indinavir. May displace other highly protein-bound drugs from plasma-protein binding sites.

Increased bioavailability (approx two-fold) with food, particularly high-fat meals (e.g. ice cream, peanuts).

Description:
Mechanism of Action: Atovaquone, a hydroxynaphthoquinone derivative, is an antiprotozoal agent with activity against the fungus Pneumocystis jirovecii (formerly known as Pneumocystis carinii). Its exact mechanism is not yet fully elucidated; however, it appears to selectively inhibit the mitochondrial electron transport chain of the parasitic protozoa and P. jirovecii by acting on the cytochrome bc1 complex (complex III), resulting in the inhibition of several metabolic enzymes responsible for nucleic acid and ATP synthesis.
Pharmacokinetics:
Absorption: Increased bioavailability (approx two-fold) with food, particularly high-fat meals. Bioavailability: Oral susp: 47% ± 15% (when given with food).
Distribution: Distributed to CSF at low concentrations (<1% of plasma concentration). Plasma protein binding: >99%.
Excretion: Via faeces (>94% as unchanged drug); urine (<1%). Elimination half-life: Approx 2-3 days.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 74989, Atovaquone. https://pubchem.ncbi.nlm.nih.gov/compound/Atovaquone. Accessed July 28, 2025.

Store between 15-25°C. Do not freeze.

Antifungals / Other Antiprotozoal Agents

P01AX06 - atovaquone ; Belongs to the class of other agents used in the treatment amoebiasis and other protozoal diseases.

Atovaquone. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 09/07/2025.

Atovaquone. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 09/07/2025.

Brayfield A, Cadart C (eds). Atovaquone. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/07/2025.

Joint Formulary Committee. Atovaquone. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/07/2025.

Mepron Suspension (GlaxoSmithKline LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/07/2025.

Wellvone 750 mg/5 mL Oral Suspension (Glaxo Wellcome UK Ltd trading as GlaxoSmithKline UK). MHRA. https://products.mhra.gov.uk. Accessed 09/07/2025.