Responses of Plasmodium falciparum infections to antimalarial drugs in north eastern Nigeria – Part 1: 1988 - 1995.

Abstract

The responses of Plasmodium falciparum strains to different antimalarial drugs were assessed in the north east of Nigeria, using a modified version of the World Health Organization (WHO) extended in vivo field test protocol from 1988 to 1995. The sensitivity of the strains to chloroquine phosphate varied from a delayed clearance of parasitaemia, through Type-RI resistance or recrudescence to asymptomatic Type-RII resistance. Chloroquine was still clinically efficacious against P. falciparum malaria and continued to play a major role in reducing malaria-related morbidity. However, parasitological failure rates were on the increase as demonstrated in Damboa, where a 1.3-fold increase occurred in D7 failure rate over a 7-year period, from 18.7% in 1988 to 24.5% in 1995. This highlighted the need for continued monitoring of the performance of the drug against the parasites, in addition to evaluating the efficacy and tolerability of new products. Second-line drugs, particularly the combinations of pyrimethamine and sulphadoxine (SD-Pyr, Fansidar®), and pyrimethamine and sulfalene (SL-Pyr, Metakelfin®) were clinically and parasitologically efficacious, producing 100% and 97.1% cure rates, respectively. Self-medication, non-compliance with treatment regimens (particularly for multiple dose therapy), sub-standard or even fake drugs/products, in addition to parasite resistance were identified as factors compounding the treatment of P. falciparum malaria.

Key Words: Antimalarial drugs; Plasmodium falciparum; North Eastern Nigeria; 1988 – 1995.

Journal of Pharmacy and Bioresources Vol.1(1) 2004: 51-60