Toxicity and side-effects of antimalarials in Africa: a critical review.

Notwithstanding the presence of resistance to chloroquine in some parts of Africa, this drug is still the most widely used antimalarial in the continent. One adverse reaction of chloroquine that has an important bearing on its use is pruritus. The risk of increasing the incidence of ocular toxicity through prolonged use of chloroquine for prophylaxis must be borne in mind by physicians. Another antimalarial that is likely to be used in increasing amounts in Africa is pyrimethamine-sulfadoxine. With prolonged use of this combination for prophylaxis, the adverse reactions usually associated with the long-acting sulfonamides are possible.Genetic abnormalities may also play a part in the incidence and severity of adverse reactions to certain drugs, e.g., primaquine and quinine. Most of the common adverse reactions are mild and have little or no influence on the acceptability and utilization of the drugs, with the exception of chloroquine-induced pruritus. Studies to define the precise epidemiology and pathophysiology of this reaction are urgently needed.