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ATOVAQUONE/PROGUANIL HYDROCHLORIDE

Medical Diagnosis and Drugs, Medications
ATOVAQUONE/PROGUANIL HYDROCHLORIDe
(a-to'va-quone/pro'gua-nil)
Malarone, Malarone Pediatric
Classifications: antimalarial;
Therapeutic: antimalarial
Prototype: Chloroquine HCl & Metronidazole
Pregnancy Category: C

Availability

Atovaquone 250 mg/proguanil HCl 100 mg, atovaquone 62.5 mg/proguanil HCl 25 mg tablets

Action

Combination of two antimalarial drugs. Atovaquone inhibits electron transport system in mitochondria of the malaria parasite, thus interfering with nucleic acid and ATP synthesis of the parasite. Proguanil interferes with DNA synthesis of the malaria parasite.

Therapeutic Effect

This drug combination has synergistic activity toward malarial treatment because each component has a different mode of action.

Uses

Prevention and treatment of malaria due to P. falciparum, even in chloroquine-resistant areas.

Contraindications

Known hypersensitivity to atovaquone or proguanil; pregnancy (category C); severe malaria.

Cautious Use

Cerebral malaria, complicated malaria, pulmonary edema; renal failure, renal impairment; hepatic disease; lactation; older adults; African Americans, Chinese, Japanese; diarrhea, emesis, GI disease; hepatic disease, infection, sunlight (UV) exposure. Use in children weighing <9 kg is not established.

Route & Dosage

Prevention of Malaria
Adult: PO 1 tablet q.d. with food starting 1–2 d before travel to malarial area and continuing for 7 d after return
Child: PO 11–20 kg, 1 pediatric tablet q.d.; 21–30 kg, 2 pediatric tablets q.d.; 31–40 kg, 3 pediatric tablets q.d.; >40 kg, 1 adult tablet q.d. with food starting 1–2 d before travel to malarial area and continuing for 7 d after return

Treatment of Malaria
Adult: PO 4 tablets as a single daily dose for 3 d
Child: PO 5–8 kg, 2 pediatric tablets; 9–10 kg, 3 pediatric tablets; 11–20 kg, 1 adult tablet; 21–30 kg, 2 adult tablets; 31–40 kg, 3 adult tablets; >40 kg, 4 adult tablets as a single daily dose for 3 d

Administration

Oral
  • Give at the same time each day with food or a drink containing milk.
  • Give a repeat dose if vomiting occurs within 1 h after dosing.

Adverse Effects (≥1%)

Body as a Whole: Fever, myalgia, back pain, asthenia, anorexia. Digestive: Nausea, abdominal pain, diarrhea, dyspepsia. CNS: Headache. Respiratory: Cough. Skin: Pruritus. Other: Anaphylactic reaction.

Interactions

Drug: Rifampin, rifabutin, tetracycline may decrease serum levels; metoclopramide may decrease absorption.

Pharmacokinetics

Absorption: Atovaquone (A), Poor, absorption improved when taken with a fatty meal; Proguanil (P), Extensively absorbed. Duration: A, 6–23 wk after a 3-wk course of therapy. Distribution: A, Penetrates poorly into cerebrospinal fluid; >99.9% protein bound; P, 75% protein bound. Metabolism: A, Not metabolized; P, Metabolized by CYP2C19 to cycloguanil. Elimination: A, >94% in feces over 21 d (enterohepatically cycled); P, Primarily in urine. Half-Life: A, 2–3 d; P, 12–21 h.

Nursing Implications

Assessment & Drug Effects

  • Lab tests: Monitor AST and ALT periodically, especially with long-term therapy.
  • Monitor for S&S of parasitemia in patients receiving tetracycline and in those experiencing diarrhea or vomiting.
  • Note: Only use metoclopramide to control vomiting if other antiemetics are not available.

Patient & Family Education

  • Take this drug at the same time each day for maximum effectiveness.
  • Note: Absorption of this drug may be reduced with diarrhea and vomiting. Consult physician if either of these occurs.

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

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