A combination of two antimalarial agents for treating and preventing Plasmodium falciparum malaria in adults and children. Malarone has been found to be effective in regions where resistance to other antimalarial drugs has developed, according to the Food and Drug Administration.
* Dosage: Treatment: four tablets a day for 3 consecutive days. Prevention: one tablet per day for adults, started 1-2 days before entering a malaria-endemic area and continued daily during the visit and for 7 days after returning. In children, dose based on body weight. (Each tablet contains 250 mg of atovaquone and 100 mg of proguanil, but a lower-dose tablet is available for children under 88 pounds.)
* Special Considerations: Not indicated for severe malaria. Side effects in adults treated with Malarone included abdominal pain, nausea, vomiting, and headache. The most common side effects in people on preventive therapy were headache and abdominal pain. Side effects in pediatric patients were vomiting and itching.
* Comment: Malarone was 98.7% effective in eight trials of over 500 adults and children weighing at least 24 pounds with acute, uncomplicated P. falciparum malaria in Africa, Asia, South America, and Europe, according to the FDA and the manufacturer. In four prevention trials in Africa, 2 of 279 patients on Malarone contracted malaria over 3 months vs. 92 of 297 on placebo. Although atovaquone alone has been found to be effective, some patients in monotherapy trials developed recurrences over time, according to Glaxo Wellcome.
Atovaquone is marketed in the United States under the trade name Mepron for Pneumocystis carinii pneumonia. Marketing of proguanil, approved for malaria in 1948, was stopped in the 1970s because it was not widely used here, although it continued to be used with other drugs in Canada and Europe.