Neutropenia associated with dual antimalarial chemoprophylaxis--use of bone-marrow culture as an aid in further drug management.

Bone-marrow culture in soft agar was used to determine the cause of neutropenia in a visitor to Tanzania who had been taking both amodiaquine and proguanil for antimalarial prophylaxis. Desethyl-amodiaquine, a major metabolite of amodiaquine (but not amodiaquine itself, proguanil, cycloguanil or chloroquine) was implicated. Supplementary studies using amodiaquine binding techniques supported the notion that the parent compound, amodiaquine, was not the cause of the neutropenia. The bone-marrow culture technique proved useful in deciding further anti-malarial prophylaxis and in formulating the choice of curative antimalarial therapy, should this have proved necessary. The procedure may help in the managing other such patients with presumed drug-induced blood dyscrasias when the choice of appropriate and effective antimalarial drugs is limited.