atovaquone, Mepron

 Indications

Treatment of mild to moderate Pneumocystis jirovecii

pneumonia (PJP) in patients who are unable to tolerate

trimethoprim/sulfamethoxazole. Prophylaxis of PJP.

Action

Inhibits the action of enzymes necessary to nucleic acid

and ATP synthesis. Therapeutic Effects: Active

against P. jirovecii.

Pharmacokinetics

Absorption: Absorption is poor but is increased by

food, particularly fat.

Distribution: Enters CSF in very low concentrations

(1% of plasma levels).

Protein Binding: 99.9%.

Metabolism and Excretion: Undergoes enterohepatic

recycling; elimination occurs in feces.

Half-life: 2.2–2.9 days.

TIME/ACTION PROFILE (blood levels)

ROUTE ONSET PEAK DURATION

PO unknown 1–8 hr; 24–

96 hr†

12 hr

†Two peaks are due to enterohepatic recycling.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Lactation:

May appear in breast milk.

Use Cautiously in:phepatic, renal, or cardiac

function (dose modification may be necessary); GI disorders

(absorption may be limited); OB: Safety not established;

Pedi: Safety not established.

Adverse Reactions/Side Effects

CNS: headache, insomnia. Resp: cough. GI: diarrhea,

nausea, vomiting. Derm: rash. Misc: fever.

Interactions

Drug-Drug: May interact with drugs that are

highly bound to plasma proteins (does not appear

to interact with phenytoin).

Drug-Food: Foodqabsorption.

Route/Dosage

Treatment

PO (Adults): 750 mg twice daily for 21 days.

PO (Children): 40 mg/kg/day (unlabeled).

Prevention

PO (Adults and Adolescents 13–16 yr): 1500 mg

once daily. 

Availability (generic available) A

Suspension: 750 mg/5 mL. In combination with:

proguanil (Malarone). See Appendix B.