A double-blind comparative clinical trial of mefloquine and chloroquine in symptomatic falciparum malaria.

A total of 99 male Zambian patients with symptomatic falciparum malaria were treated in a double-blind randomized manner with either mefloquine (1000 mg given in one day) or chloroquine (1500 mg given over 3 days). An S-type response was seen in all the chloroquine patients and 98% of the mefloquine group; one patient in the latter group (2%) showed an RI-type response, but the parasites obtained during the recrudescence were sensitive to both chloroquine and mefloquine in the in vitro microtest, and the patient responded satisfactorily to oral chloroquine. The rate of clearance of parasitaemia was marginally faster in the chloroquine-treated group. The rate of clearance of fever was similar in the two groups. Both drugs were well tolerated and side-effects such as nausea, vomiting, dizziness, loose stools, and pruritus were mild and transient. Pruritus was more common after chloroquine administration and dizziness more common in the mefloquine group. There were no drug-induced alterations in the haematological and biochemical profiles.