Lack of effect of desipramine on the response to chloroquine of patients with chloroquine-resistant falciparum malaria

The potential of desipramine to improve the efficacy of chloroquine against chloroquine-resistant Plasmodium falciparum in vivo in man was investigated. Fifty-three malaria patients were selected according to the criteria for the standard World Health Organization (WHO) in vivo test and were randomly divided in 2 groups. One group (n = 27) was given standard therapeutic doses of chloroquine (25 mg/kg body weight of base) and the other (n = 26) was given standard doses of chloroquine, as above, in combination with desipramine (1.3-2.8 mg/kg body weight) daily for 3 consecutive days. Standard WHO in vitro micro-tests were performed in parallel with the tests in vivo to provide chloroquine sensitivity patterns of the P. falciparum parasites. The results in vitro from both groups did not differ with regard to chloroquine sensitivity and the means of the pre-treatment parasite densities were similar. There was no apparent difference in parasite clearance in vivo between the 2 groups. This study provided no evidence for enhanced chloroquine efficacy in vivo through the use of desipramine in doses corresponding to the usual therapeutic range.