Abstract
Pyrimethamine-sulfadoxine, the first choice for uncomplicated falciparum malaria in Africa, exerts strong selection pressure for resistance because of its slow elimination. It is likely that resistance will emerge rapidly, and there is no widely affordable replacement. Chlorproguanil-dapsone is cheap, rapidly eliminated, more potent than pyrimethamine-sulfadoxine, and could be introduced in the near future to delay the onset of antifolate resistance and as "salvage therapy" for pyrimethamine-sulfadoxine failure. A total of 448 children were randomly allocated (double blind) to either a single dose of pyrimethamine-sulfadoxine or to one of two chlorproguanil-dapsone regimens: a single dose or three doses at 24-h intervals. Reinfections are clinically indistinguishable from recrudescence and are more likely after treatment with rapidly eliminated drugs; we measured the incidence of parasitemia in 205 initially aparasitemic children to allow comparison with the three treatment groups. The patients and a community surveillance group were followed up for 28 days. At the study end point, 31.2% (95% confidence interval, 24.9-38.0) of the community surveillance group subjects were parasitemic, compared with subjects in the treatment groups, whose rates of parasitemia were 40.8% (32.9-49.0; relative risk [RR], 1.31 [0.99-1.73]) after triple-dose chlorproguanil-dapsone, 19.7% (13.5-27.2; RR, 0.63 [0.43-0.93]) after pyrimethamine-sulfadoxine, and 65.6% (57.5-73.0; RR, 2.10 [1.66-2.65]) after single-dose chlorproguanil-dapsone. Pyrimethamine-sulfadoxine and triple-dose chlorproguanil-dapsone were effective treatments. Pyrimethamine-sulfadoxine provided chemoprophylaxis during follow-up because of its slow elimination. Triple-dose chlorproguanil-dapsone should now be developed in an attempt to reduce the rate of emergence of antifolate resistance in Africa and for affordable salvage therapy in cases of pyrimethamine-sulfadoxine failure.
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- Bloland P. B., Lackritz E. M., Kazembe P. N., Were J. B., Steketee R., Campbell C. C. Beyond chloroquine: implications of drug resistance for evaluating malaria therapy efficacy and treatment policy in Africa. J Infect Dis. 1993 Apr;167(4):932–937. doi: 10.1093/infdis/167.4.932. [DOI] [PubMed] [Google Scholar]
- Brandling-Bennett A. D., Oloo A. J., Watkins W. M., Boriga D. A., Kariuki D. M., Collins W. E. Chloroquine treatment of falciparum malaria in an area of Kenya of intermediate chloroquine resistance. Trans R Soc Trop Med Hyg. 1988;82(6):833–837. doi: 10.1016/0035-9203(88)90009-0. [DOI] [PubMed] [Google Scholar]
- Brooks D. R., Wang P., Read M., Watkins W. M., Sims P. F., Hyde J. E. Sequence variation of the hydroxymethyldihydropterin pyrophosphokinase: dihydropteroate synthase gene in lines of the human malaria parasite, Plasmodium falciparum, with differing resistance to sulfadoxine. Eur J Biochem. 1994 Sep 1;224(2):397–405. doi: 10.1111/j.1432-1033.1994.00397.x. [DOI] [PubMed] [Google Scholar]
- Foote S. J., Galatis D., Cowman A. F. Amino acids in the dihydrofolate reductase-thymidylate synthase gene of Plasmodium falciparum involved in cycloguanil resistance differ from those involved in pyrimethamine resistance. Proc Natl Acad Sci U S A. 1990 Apr;87(8):3014–3017. doi: 10.1073/pnas.87.8.3014. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hyde J. E. The dihydrofolate reductase-thymidylate synthetase gene in the drug resistance of malaria parasites. Pharmacol Ther. 1990;48(1):45–59. doi: 10.1016/0163-7258(90)90017-v. [DOI] [PubMed] [Google Scholar]
- Mwenesi H., Harpham T., Snow R. W. Child malaria treatment practices among mothers in Kenya. Soc Sci Med. 1995 May;40(9):1271–1277. doi: 10.1016/0277-9536(94)00250-w. [DOI] [PubMed] [Google Scholar]
- Nevill C. G., Some E. S., Mung'ala V. O., Mutemi W., New L., Marsh K., Lengeler C., Snow R. W. Insecticide-treated bednets reduce mortality and severe morbidity from malaria among children on the Kenyan coast. Trop Med Int Health. 1996 Apr;1(2):139–146. doi: 10.1111/j.1365-3156.1996.tb00019.x. [DOI] [PubMed] [Google Scholar]
- Newton C. R., Winstanley P. A., Watkins W. M., Mwangi I. N., Waruiru C. M., Mberu E. K., Warn P. A., Nevill C. G., Marsh K. A single dose of intramuscular sulfadoxine-pyrimethamine as an adjunct to quinine in the treatment of severe malaria: pharmacokinetics and efficacy. Trans R Soc Trop Med Hyg. 1993 Mar-Apr;87(2):207–210. doi: 10.1016/0035-9203(93)90495-c. [DOI] [PubMed] [Google Scholar]
- Patchen L. C., Mount D. L., Schwartz I. K., Churchill F. C. Analysis of filter-paper-absorbed, finger-stick blood samples for chloroquine and its major metabolite using high-performance liquid chromatography with fluorescence detection. J Chromatogr. 1983 Nov 11;278(1):81–89. doi: 10.1016/s0378-4347(00)84758-1. [DOI] [PubMed] [Google Scholar]
- Peterson D. S., Milhous W. K., Wellems T. E. Molecular basis of differential resistance to cycloguanil and pyrimethamine in Plasmodium falciparum malaria. Proc Natl Acad Sci U S A. 1990 Apr;87(8):3018–3022. doi: 10.1073/pnas.87.8.3018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Plowe C. V., Djimde A., Wellems T. E., Diop S., Kouriba B., Doumbo O. K. Community pyrimethamine-sulfadoxine use and prevalence of resistant Plasmodium falciparum genotypes in Mali: a model for deterring resistance. Am J Trop Med Hyg. 1996 Nov;55(5):467–471. doi: 10.4269/ajtmh.1996.55.467. [DOI] [PubMed] [Google Scholar]
- Radloff P. D., Philipps J., Nkeyi M., Hutchinson D., Kremsner P. G. Atovaquone and proguanil for Plasmodium falciparum malaria. Lancet. 1996 Jun 1;347(9014):1511–1514. doi: 10.1016/s0140-6736(96)90671-6. [DOI] [PubMed] [Google Scholar]
- Snewin V. A., England S. M., Sims P. F., Hyde J. E. Characterisation of the dihydrofolate reductase-thymidylate synthetase gene from human malaria parasites highly resistant to pyrimethamine. Gene. 1989 Mar 15;76(1):41–52. doi: 10.1016/0378-1119(89)90006-1. [DOI] [PubMed] [Google Scholar]
- Snow R. W., Schellenberg J. R., Peshu N., Forster D., Newton C. R., Winstanley P. A., Mwangi I., Waruiru C., Warn P. A., Newbold C. Periodicity and space-time clustering of severe childhood malaria on the coast of Kenya. Trans R Soc Trop Med Hyg. 1993 Jul-Aug;87(4):386–390. doi: 10.1016/0035-9203(93)90007-d. [DOI] [PubMed] [Google Scholar]
- Sudre P., Breman J. G., McFarland D., Koplan J. P. Treatment of chloroquine-resistant malaria in African children: a cost-effectiveness analysis. Int J Epidemiol. 1992 Feb;21(1):146–154. doi: 10.1093/ije/21.1.146. [DOI] [PubMed] [Google Scholar]
- Triglia T., Cowman A. F. Primary structure and expression of the dihydropteroate synthetase gene of Plasmodium falciparum. Proc Natl Acad Sci U S A. 1994 Jul 19;91(15):7149–7153. doi: 10.1073/pnas.91.15.7149. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Watkins W. M., Brandling-Bennett A. D., Nevill C. G., Carter J. Y., Boriga D. A., Howells R. E., Koech D. K. Chlorproguanil/dapsone for the treatment of non-severe Plasmodium falciparum malaria in Kenya: a pilot study. Trans R Soc Trop Med Hyg. 1988;82(3):398–403. doi: 10.1016/0035-9203(88)90133-2. [DOI] [PubMed] [Google Scholar]
- Watkins W. M., Chulay J. D., Sixsmith D. G., Spencer H. C., Howells R. E. A preliminary pharmacokinetic study of the antimalarial drugs, proguanil and chlorproguanil. J Pharm Pharmacol. 1987 Apr;39(4):261–265. doi: 10.1111/j.2042-7158.1987.tb06263.x. [DOI] [PubMed] [Google Scholar]
- Watkins W. M., Mosobo M. Treatment of Plasmodium falciparum malaria with pyrimethamine-sulfadoxine: selective pressure for resistance is a function of long elimination half-life. Trans R Soc Trop Med Hyg. 1993 Jan-Feb;87(1):75–78. doi: 10.1016/0035-9203(93)90431-o. [DOI] [PubMed] [Google Scholar]
- Winstanley P. A., Mberu E. K., Szwandt I. S., Breckenridge A. M., Watkins W. M. In vitro activities of novel antifolate drug combinations against Plasmodium falciparum and human granulocyte CFUs. Antimicrob Agents Chemother. 1995 Apr;39(4):948–952. doi: 10.1128/aac.39.4.948. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winstanley P. A., Watkins W. M., Newton C. R., Nevill C., Mberu E., Warn P. A., Waruiru C. M., Mwangi I. N., Warrell D. A., Marsh K. The disposition of oral and intramuscular pyrimethamine/sulphadoxine in Kenyan children with high parasitaemia but clinically non-severe falciparum malaria. Br J Clin Pharmacol. 1992 Feb;33(2):143–148. doi: 10.1111/j.1365-2125.1992.tb04016.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winstanley P. Pyronaridine: a promising drug for Africa? Lancet. 1996 Jan 6;347(8993):2–3. doi: 10.1016/s0140-6736(96)91548-2. [DOI] [PubMed] [Google Scholar]
- Winstanley P., Watkins W., Muhia D., Szwandt S., Amukoye E., Marsh K. Chlorproguanil/dapsone for uncomplicated Plasmodium falciparum malaria in young children: pharmacokinetics and therapeutic range. Trans R Soc Trop Med Hyg. 1997 May-Jun;91(3):322–327. doi: 10.1016/s0035-9203(97)90093-6. [DOI] [PubMed] [Google Scholar]