Potential toxicity of chlorpheniramine plus chloroquine for the treatment of childhood malaria.

OBJECTIVES To compare the adverse effects of two regimens of chlorpheniramine plus chloroquine (CP+CQ) in children who live in a country where chloroquine resistant malaria is endemic. METHODS 99 children with acute uncomplicated malaria were randomised into two treatment groups. Group I received high dose chlorpheniramine (6 mg +12 mg/day for 7 days in children = 5 years; 8 mg + 18 mg/day for 7 days in those >5 years) plus chloroquine 10 mg/kg daily for 3 days. Group II received a 50% higher dose of chlorpheniramine plus chloroquine 10 mg/kg daily for 3 days. Outcome measures were vital signs, clinical response and parasite clearance on days 0-7 and day 14. RESULTS Parasite clearance, fever clearance and cure rate were comparable for the two groups. Drowsiness occurred in 66.7% of high dose and 86.3% of higher dose CP+CQ subjects (p = 0.05). Compared to children treated with high dose, those treated with higher dose CP+CQ had significantly lower respiratory rates on day 2 (p = 0.001), day 6 (p = 0.015), and on day 14 (p = 0.003). CONCLUSION The higher rates of drowsiness and lower respiratory rates in children treated with higher dose CP+CQ calls for caution in the clinical application of the higher dose combination. The higher dose has no additional benefit and may in fact be dangerous.