THERAPEUTIC EFFECTS OF CHLOROQUINE IN COMBINATION WITH QUININE IN UNCOMPLICATED FALCIPARUM-MALARIA

The efficacy and toxicity of oral quinine combined with oral chloroqui ne were studied in 50 Thai men with uncomplicated falciparum malaria. All mere treated for 7 days with quinine sulphate (10 mgr salt/kg ever y 8 h). Twenty-five of the patients, selected at random, were also giv en oral tetracycline (4 mg/kg four times daily) over the same period a nd the remainder were given chloroquine (25 mg base/kg over the first 3 days). There were no serious adverse effects. Overall fever-clearanc e times (FCT) and parasite-clearance times (PCT) in the chloroquine an d tetracycline groups were not significantly different, with mean (s.D .) values of 51 (33) and 41 (27) h for FCT and 80 (25) and 83 (21) h f or PCT, respectively. Most of the patients (18 in each group) were fol lowed for greater than or equal to 2 months. Recrudescence rates (R1) were significantly higher in the chloroquine group than in the tetracy cline group (39% v. 6%; P=0.02), all recrudescences occurring within 4 weeks (18-25 days) of starting treatment. Subsequent parasitaemia wit h Plasmodium vivax, however, occurred less frequently in the chloroqui ne group (11%) than in the tetracycline group (33%) (P=0.11) and took longer to develop in the chloroquine group [51 or 59 days compared wit h a mean (s.D.) value of 29 (10) days in the tetracycline group; P=0.0 1]. Within the chloroquine group, FCT and PCT were both shorter in tho se with cure than in those with R1 resistance, with mean (s.D.) values of 41 (25) and 50 (33)h for FCT (P=0.09) and 72 (20) and 100 (18)h fo r PCT (P=0.01), respectively. Chloroquine does not potentiate the clin ical response to quinine against resistant strains of uncomplicated fa lciparum malaria, nor does it convey any useful antipyretic effect.