Norfloxacin is inferior to chloroquine for falciparum malaria in northwestern Zambia: a comparative clinical trial.

Fluoroquinolones are active against Plasmodium falciparum in vitro. In a prospective, randomized, comparative trial, norfloxacin, 400 mg twice a day for 3 days, was compared with a standard course of chloroquine in semiimmune adults with symptomatic falciparum malaria in northwestern Zambia, where chloroquine resistance is uncommon. Patients were followed for 28 days. The trial was terminated after 38 patients were studied because chloroquine was markedly more effective, curing all 18 patients (100%) compared with only 8 (40%) of 20 who received norfloxacin (P less than .001). Of the 12 norfloxacin failures, 6 had clearing of trophozoites but recurrence during the study period (RI), 4 had incomplete clearance of trophozoites with later recurrence (RII), and 2 had no improvement (RIII). The mean parasite clearance time was significantly shorter with chloroquine (30.4 vs. 52.7 h; P = .02). The mean defervescence time was also shorter with chloroquine (16.9 vs. 24.5 h; not significant). In contrast to its inferior efficacy, norfloxacin caused fewer adverse effects than did chloroquine (33% vs. 0; P less than .001).