A controlled trial to assess the effect of quinine, chloroquine, amodiaquine, and artesunate on Loa loa microfilaremia

Abstract

Onchocerciasis control is currently based on mass ivermectin treatment. Unfortunately, this drug can induce serious adverse events (SAEs) in persons with high levels of Loa loa microfilaremia (> 30,000 microfilaria/mL). A means of preventing SAEs would be to treat at risk populations with a drug that would progressively reduce the microfilarial loads before administering ivermectin. Antimalarial drugs are a potential solution because they have shown some activity against various filarial species. A controlled trial was conducted to assess the effect of standard doses of quinine, chloroquine, amodiaquine, and artesunate on L. loa microfilaremia. Ninety-eight patients were randomly allocated into five groups (one for each drug and a control group) after stratification on microfilarial load. Loa loa microfilaremia was monitored on days 0, 3, 7, 15, 30, 60, and 90. No significant change in the loads was recorded in any of the treatment groups. A comprehensive review of the effects of antimalarial drugs against filariae is also provided.

Figure 1.

Individual follow-up of Loa loa microfilaremia in the five treatment groups (quinine, 1,200 mg/day for 5 days; chloroquine, 600 mg/day for 3 days; amodiaquine, 800 mg/day for 3 days; artesunate, 200 mg/day for 3 days; control group, persons receiving iron-folic acid tablets). Thick lines represent the geometric mean numbers of Loa loa microfilaria per milliliter of blood.