Controlled Trial of 3-Day Quinine-Clindamycin Treatment versus 7-Day Quinine Treatment for Adult Travelers with Uncomplicated Falciparum Malaria Imported from the Tropics

Resistance to the amino alcohol quinine has been associated with polymorphisms in pfnhe, a sodium hydrogen exchanger. We investigated the role of this gene in quinine resistance in vitro in isolates from Kenya. We analyzed pfnhe whole-gene polymorphisms, using capillary sequencing, and pfcrt at codon 76 (pfcrt-76) and pfmdr1 at codon 86 (pfmdr1-86), using PCR-enzyme restriction methodology, in 29 isolates from Kilifi, Kenya, for association with the in vitro activities of quinine and 2 amino alcohols, mefloquine and halofantrine. In vitro activity was assessed as the drug concentration that inhibits 50% of parasite growth (IC 50 ). The median IC 50 s of quinine, halofantrine, and mefloquine were 92, 22, and 18 nM, respectively. The presence of 2 DNNND repeats in microsatellite ms4760 of pfnhe was associated with reduced susceptibility to quinine (60 versus 227 nM for 1 and 2 repeats, respectively; P < 0.05), while 3 repeats were associated with restoration of susceptibility. The decrease in susceptibility conferred by the 2 DNNND repeats was more pronounced in parasites harboring the pfmdr1-86 mutation. No association was found between susceptibility to quinine and the pfcrt-76 mutation or between susceptibility to mefloquine or halofantrine and the pfnhe gene and the pfcrt-76 and pfmdr1-86 mutations. Using previously published data on the in vitro activities of chloroquine, lumefantrine, piperaquine, and dihydroartemisinin, we investigated the association of their activities with pfnhe polymorphism. With the exception of a modulation of the activity of lumefantrine by a mutation at position 1437, pfnhe did not modulate their activities. Two DNNND repeats combined with the pfmdr1-86 mutation could be used as an indicator of reduced susceptibility to quinine.The amino alcohol quinine (QN) remains one of the important drugs against malaria. It is the drug of choice for the treatment of severe malaria, and in most African countries, including Kenya, where artemisinin-based combinations (lumefantrine-artemether, amodiaquine-artesunate) are now first-line treatments, 7-day quinine monotherapy has become the second-line treatment for uncomplicated malaria (44). However, there is evidence of selection and spread of QN-resistant parasites or those with reduced susceptibility to 8,30,34). This observation led to the investigation of artesunate (an artemisinin derivative) as an alternative to QN for the treatment of severe malaria (14). However, this option could now be compromised by the emergence of artemisinin resistance (9).Several studies have been dedicated to understanding the mechanisms of quinine resistance. Polymorphisms in pfmdr, a gene associated with chloroquine (CQ) resistance, modulate QN susceptibility (27,33,36). A mutation of the CQ resistance gene pfcrt at codon 76 (pfcrt-76) has been associated with reduced susceptibility to QN in vitro, although transfection studies have shown conflicting results (16,37). A seminal study on the association of polymorphisms in pfnhe, a sodium hydrogen exchanger gene, a...

Section: Resultsmentioning

confidence: 92%

In Vitro Activities of Quinine and Other Antimalarials and pfnhe Polymorphisms in Plasmodium Isolates from Kenya

Okombo

Kiara

Rono

et al. 2010

“…A quinine-clindamycin combination was effective against multidrug-resistant malaria in Thailand (20). Furthermore, a 3-day course of clindamycin plus quinine was curative in the treatment of uncomplicated P. falciparum malaria, compared to 7 days of treatment with quinine alone (19). Since clindamycin has been used only for a relatively small number of malaria patients, it is not expected that resistant parasites have developed in the field.…”

Section: Discussionmentioning

confidence: 99%

In Vitro and In Vivo Synergy of Fosmidomycin, a Novel Antimalarial Drug, with Clindamycin

Wiesner¹,

Henschker²,

Hutchinson³

et al. 2002

126

106

Fosmidomycin acts through inhibition of 1-deoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase, a key enzyme of the nonmevalonate pathway of isoprenoid biosynthesis. It possesses potent antimalarial activity in vitro and in murine malaria. In a recent clinical study, fosmidomycin was effective and well tolerated in the treatment of patients with acute uncomplicated Plasmodium falciparum malaria but resulted in an unacceptably high rate of recrudescence. In order to identify a potential combination partner, the interaction of fosmidomycin with a number of antimalarial drugs in current use was investigated in a series of in vitro experiments. Synergy was observed between fosmidomycin and the lincosamides, lincomycin and clindamycin. The efficacy of a combination of fosmidomycin and clindamycin was subsequently demonstrated in the Plasmodium vinckei mouse model.In humans, isoprenoids are synthesized via the mevalonate pathway. In contrast, they are synthesized by the nonmevalonate pathway (the 1-deoxy-D-xylulose 5-phosphate [DOXP] pathway, also called the MEP pathway) in a number of bacterial species and inside the plastides of algae and higher plants (22). Similarly, the enzymes of the nonmevalonate pathway are located inside the plastide-like organelle (apicoplast) of malaria parasites (7,27). The antibiotic fosmidomycin, originally isolated from Streptomyces lavendulae, represents a potent inhibitor of DOXP reductoisomerase, a key enzyme of the nonmevalonate pathway (15,28). Recently, it was demonstrated that fosmidomycin possesses potent antimalarial activity in vitro and in murine malaria (7). FR900098, a fosmidomycin derivative, was found to be twice as effective, while the prodrug derivatives had increased oral bioavailability in the mouse model (21).In a recent clinical study conducted in Gabon and Thailand, 20 patients with acute uncomplicated Plasmodium falciparum malaria were treated with fosmidomycin administered orally (B. Lell, R. Ruangweerayut, J. Wiesner, M. Missinou, A. Schindler, T. Baranek, M. Hintz, D. Hutchinson, H. Jomaa, and P. Kremsner, unpublished data). The treatment was well tolerated and resulted in rapid parasite and fever clearance times, comparable to those obtained with conventional quinoline antimalarial agents. All patients were clinically and parasitologically cured by day 7. By day 28, however, 9 out of 18 evaluable patients experienced recrudescence. A similarly high rate of recrudescence had been observed previously when the hydroxynaphthoquinone antimalarial agent atovaquone was evaluated as a single entity (17). Subsequently, proguanil was identified as a partner for atovaquone on the basis of in vitro synergistic activity, resulting in a highly effective and welltolerated fixed drug combination, approved and marketed as Malarone (3). Using a similar approach, we have investigated the interaction of fosmidomycin with most antimalarial agents in clinical use. MATERIALS AND METHODSMaterials. Blood components were provided by the local Institute of Clinical Immunology and Tran...

“…The log-rank test showed that the rate of parasite clearance did not differ in the two arms. on April 8, 2019 by guest http://aac.asm.org/ these patients are similar to those with imported malaria in Europe described previously (8). This study had several limitations.…”

Section: Discussionmentioning

confidence: 82%

“…Newer regimens, including the fixed combinations of atovaquone-proguanil and artemether-lumefantrine, are slowly being introduced, even in the absence of efficacy data from randomized trials with nonimmune subjects. When infections are sensitive to quinine, a 3-day course of quinine and sulfadoxine-pyrimethamine can be given to overcome the problem of poor compliance with longer regimens (4,8,16). Sulfadoxine-pyrimethamine resistance occurs frequently in Southeast Asia and South America and occurs to such an extent that these combinations have questionable efficacies against infections acquired in these areas.…”

mentioning

confidence: 99%

Mefloquine versus Quinine plus Sulphalene-Pyrimethamine (Metakelfin) for Treatment of Uncomplicated Imported Falciparum Malaria Acquired in Africa

Matteelli

Saleri

Bisoffi

et al. 2005

We conducted a multicenter, randomized, open-label trial to compare mefloquine with a 3-day quinine plus sulphalene-pyrimethamine (SP) regimen for the treatment of imported uncomplicated malaria acquired in Africa. The end points of the study were efficacy, tolerability, and length of hospital stay. From July 1999 to February 2003, 187 patients were enrolled in five centers in Italy, of whom 93 were randomized to receive mefloquine (the M group) and 94 were randomized to receive quinine plus SP (the QSP group). Immigrants and visiting relatives and friends represented 90% of the cases and were mainly from western African countries. A slightly increased proportion of cases in the QSP group had abnormal alanine aminotransferase levels at the baseline. The early cure rate was similar in the two groups: 98.9% (confidence interval [CI] ‫؍‬ 97 to 100%) in the M group and 96.8% (CI ‫؍‬ 93 to 100%) in the QSP group. The extended follow-up was completed by 135 subjects (72.2%), and no case of recrudescence was detected. There were no differences in the parasite clearance time, but patients in the M group had shorter mean fever clearance time (35.9 h versus 44.4 h for the QSP group; P ‫؍‬ 0.05) and a shorter mean hospital stay (3.9 days versus 4.6 days for the QSP group; P ‫؍‬ 0.007). The overall proportions of reported side effects were similar in the two groups, but patients in the M group had a significantly higher rate of central nervous system disturbances (29.0% versus 9.6% for the QSP group; P < 0.001).