Predictors of mefloquine treatment failure: A prospectivestudy of 1590 patients with uncomplicated falciparum malaria: A prospectivestudy of 1590 patients with uncomplicated falciparum malaria

The factors which identify patients at risk of treatment failure were characterized in 1590 children and adults with uncomplicated falciparum malaria treated with 15 or 25 mg/kg of mefloquine on the borders of Thailand. Six independent predictors of failure were identified using multiplelogistic regression. Age ≤2 years (odds ratio [OR] 4.54), 3-15 years (OR 4.4), vomiting <30 min after a single dose of 25 mg/kg (despite re-administration of the dose) (OR 2.5) and diarrhoea after treatment (OR 3.6) were the strongest predictors of failure by day 7. Parasitaemias >10 000/mm3 (OR 1.4), and fever with a history of recent vomiting (OR 1.6) were risk factors for recrudescence of the infection between days 10 and 28. Patients treated with mefloquine in the previous 2 months were also at increased risk of failure (OR 2.38), particularly if they were anaemic (haematocrit <30%) (OR 5.96), which suggested that they had recrudescentinfections at presentation. Combined, these 6 factors identified half of all treatment failures. Vomitingand diarrhoea accounted for 24% of the early failures in children. Patients at increased riskof treatment failure should be monitored closely and given early alternative treatment if fever andparasites persist for ≥3 d.