Comparison of the parasitologic efficacy of amodiaquine and sulfadoxine-pyrimethamine in the treatment of Plasmodium falciparum malaria in the Bungoma District of western Kenya

Faculty of Medicine, and Department of Infectious Diseases, Tropical Medicine and AIDS, University of Amsterdam, Academic Medical Center, Amsterdam, The Netherlands.
The American journal of tropical medicine and hygiene (Impact Factor: 2.7). 11/2004; 71(5):537-41.
Source: PubMed


The efficacy of amodiaquine (AQ) and sulfadoxine-pyrimethamine (SP) was assessed in 310 symptomatic children from western Kenya with uncomplicated Plasmodium falciparum malaria. A non-blinded, randomized, 14-day study was performed and parasitologic criteria were used. Of 310 patients included, 238 (77%) completed the study: 120 received AQ and 118 received SP. In those treated with AQ, there were sensitive (S) infections in 107 patients (89.2%, 95% confidence interval [CI] = 82.2, 94.1%), RI resistance in 10 (8.3%, 95% CI = 4.1, 14.8%), RII resistance in 1 (0.8%, 95% CI = 0, 4.6%), and RIII resistance in 2 (1.7%, 95% CI = 0.2, 5.9%). In those treated with SP, there were S infections in 74 patients (62.7%, 95% CI = 53.3, 71.4%), RI resistance in 21 (17.8%, 95% CI = 11.4, 25.9%), RII resistance in 11 (9.3%, 95% CI = 4.7, 16.1%), and RIII resistance in 12 (10.2%, 95% CI = 5.4, 17.1%). Resistance rates were consistently higher in the SP-treated patients (P < 0.001). Resistance to SP in this area has reached such levels that it should no longer be the first-line treatment. Alternative treatment, such as SP plus AQ combination treatment or artemisinin combination treatment, is urgently needed.

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Available from: Frank Cobelens, Dec 20, 2013
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    • "AL has been the recommended first line treatment for uncomplicated malaria in Kenya since 2006. SP is still widely available and used, but resistance is common; more than 80% of infections are resistant [20] resulting in 22-40% treatment failure [21,22]. Forty-four percent of malaria medicine retailers had AL in stock on the day of the survey, and an additional 20% reported stocking it but were out of stock that day. "
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    ABSTRACT: Poor access to prompt and effective treatment for malaria contributes to high mortality and severe morbidity. In Kenya, it is estimated that only 12% of children receive anti-malarials for their fever within 24 hours. The first point of care for many fevers is a local medicine retailer, such as a pharmacy or chemist. The role of the medicine retailer as an important distribution point for malaria medicines has been recognized and several different strategies have been used to improve the services that these retailers provide. Despite these efforts, many mothers still purchase ineffective drugs because they are less expensive than effective artemisinin combination therapy (ACT). One strategy that is being piloted in several countries is an international subsidy targeted at anti-malarials supplied through the retail sector. The goal of this strategy is to make ACT as affordable as ineffective alternatives. The programme, called the Affordable Medicines Facility - malaria was rolled out in Kenya in August 2010. In December 2010, the affordability and accessibility of malaria medicines in a rural district in Kenya were evaluated using a complete census of all public and private facilities, chemists, pharmacists, and other malaria medicine retailers within the Webuye Demographic Surveillance Area. Availability, types, and prices of anti-malarials were assessed. There are 13 public or mission facilities and 97 medicine retailers (registered and unregistered). The average distance from a home to the nearest public health facility is 2 km, but the average distance to the nearest medicine retailer is half that. Quinine is the most frequently stocked anti-malarial (61% of retailers). More medicine retailers stocked sulphadoxine-pyramethamine (SP; 57%) than ACT (44%). Eleven percent of retailers stocked AMFm subsidized artemether-lumefantrine (AL). No retailers had chloroquine in stock and only five were selling artemisinin monotherapy. The mean price of any brand of AL, the recommended first-line drug in Kenya, was $2.7 USD. Brands purchased under the AMFm programme cost 40% less than non-AMFm brands. Artemisinin monotherapies cost on average more than twice as much as AMFm-brand AL. SP cost only $0.5, a fraction of the price of ACT. AMFm-subsidized anti-malarials are considerably less expensive than unsubsidized AL, but the price difference between effective and ineffective therapies is still large.
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    • "Although currently available evidence regarding the efficacy of IPTi with SP is promising [7], [9]–[14], the protective efficacy of IPTi with SP in more recent trials has been more modest than the initial Tanzania trial, and a recent study reported no protective efficacy of IPTi with SP [15]. In addition, Plasmodium falciparum resistance to SP is high in sub-Saharan Africa [16], [17], and alternative drugs for this strategy need to be identified. The mechanism by which IPTi works is not well understood: it is unknown whether the intermittent clearance of existing malaria infections (treatment effect) or the post-treatment prophylactic effect of long-acting drugs is more important [18]. "
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    ABSTRACT: Intermittent preventive treatment in infants (IPTi) with sulphadoxine-pyrimethamine (SP) for the prevention of malaria has shown promising results in six trials. However, resistance to SP is rising and alternative drug combinations need to be evaluated to better understand the role of treatment versus prophylactic effects. Between March 2004 and March 2008, in an area of western Kenya with year round malaria transmission with high seasonal intensity and high usage of insecticide-treated nets, we conducted a randomized, double-blind placebo-controlled trial with SP plus 3 days of artesunate (SP-AS3), 3 days of amodiaquine-artesunate (AQ3-AS3), or 3 days of short-acting chlorproguanil-dapsone (CD3) administered at routine expanded programme of immunization visits (10 weeks, 14 weeks and 9 months). 1,365 subjects were included in the analysis. The incidence of first or only episode of clinical malaria during the first year of life (primary endpoint) was 0.98 episodes/person-year in the placebo group, 0.74 in the SP-AS3 group, 0.76 in the AQ3-AS3 group, and 0.82 in the CD3 group. The protective efficacy (PE) and 95% confidence intervals against the primary endpoint were: 25.7% (6.3, 41.1); 25.9% (6.8, 41.0); and 16.3% (-5.2, 33.5) in the SP-AS3, AQ3-AS3, and CD3 groups, respectively. The PEs for moderate-to-severe anaemia were: 27.5% (-6.9, 50.8); 23.1% (-11.9, 47.2); and 11.4% (-28.6, 39.0). The duration of the protective effect remained significant for up to 5 to 8 weeks for SP-AS3 and AQ3-AS3. There was no evidence for a sustained beneficial or rebound effect in the second year of life. All regimens were well tolerated. These results support the view that IPTi with long-acting regimens provide protection against clinical malaria for up to 8 weeks even in the presence of high ITN coverage, and that the prophylactic rather than the treatment effect of IPTi appears central to its protective efficacy.
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    • "Vector abundance is an important determinant of malaria transmission force (Garrett-Jones 1964) and thus factors that increase or decrease vector abundance will have an impact on prevalence of the disease . Intervention using antimalaria drugs has been used as the primary tool for malaria control; however, increasing drug resistance has weakened this strategic tool (Vreugdenhil et al. 2004, Whitty et al. 2004). "
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