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BackgroundArtesunate-amodiaquine (AS-AQ) is one of the most widely used artemisinin-based combination therapies (ACTs) to treat uncomplicated Plasmodium falciparum malaria in Africa. We investigated the impact of different dosing strategies on the efficacy of this combination for the treatment of falciparum malaria.MethodsIndividual patient data from AS-AQ clinical trials were pooled using the WorldWide Antimalarial Resistance Network (WWARN) standardised methodology. Risk factors for treatment failure were identified using a Cox regression model with shared frailty across study sites.ResultsForty-three studies representing 9,106 treatments from 1999-2012 were included in the analysis; 4,138 (45.4%) treatments were with a fixed dose combination with an AQ target dose of 30 mg/kg (FDC), 1,293 (14.2%) with a non-fixed dose combination with an AQ target dose of 25 mg/kg (loose NFDC-25), 2,418 (26.6%) with a non-fixed dose combination with an AQ target dose of 30 mg/kg (loose NFDC-30), and the remaining 1,257 (13.8%) with a co-blistered non-fixed dose combination with an AQ target dose of 30 mg/kg (co-blistered NFDC). The median dose of AQ administered was 32.1 mg/kg [IQR: 25.9-38.2], the highest dose being administered to patients treated with co-blistered NFDC (median = 35.3 mg/kg [IQR: 30.6-43.7]) and the lowest to those treated with loose NFDC-25 (median = 25.0 mg/kg [IQR: 22.7-25.0]). Patients treated with FDC received a median dose of 32.4 mg/kg [IQR: 27-39.0]. After adjusting for reinfections, the corrected antimalarial efficacy on day 28 after treatment was similar for co-blistered NFDC (97.9% [95% confidence interval (CI): 97.0-98.8%]) and FDC (98.1% [95% CI: 97.6%-98.5%]; P = 0.799), but significantly lower for the loose NFDC-25 (93.4% [95% CI: 91.9%-94.9%]), and loose NFDC-30 (95.0% [95% CI: 94.1%-95.9%]) (P

Abstract Background Artesunate and amodiaquine (AS&AQ) is at present the world's second most widely used artemisinin-based combination therapy (ACT). It was necessary to evaluate the efficacy of ACT, recently adopted by the World Health Organization (WHO) and deployed over 80 countries, in order to make an evidence-based drug policy. Methods An individual patient data (IPD) analysis was conducted on efficacy outcomes in 26 clinical studies in sub-Saharan Africa using the WHO protocol with similar primary and secondary endpoints. Results A total of 11,700 patients (75% under 5 years old), from 33 different sites in 16 countries were followed for 28 days. Loss to follow-up was 4.9% (575/11,700). AS&AQ was given to 5,897 patients. Of these, 82% (4,826/5,897) were included in randomized comparative trials with polymerase chain reaction (PCR) genotyping results and compared to 5,413 patients (half receiving an ACT). AS&AQ and other ACT comparators resulted in rapid clearance of fever and parasitaemia, superior to non-ACT. Using survival analysis on a modified intent-to-treat population, the Day 28 PCR-adjusted efficacy of AS&AQ was greater than 90% (the WHO cut-off) in 11/16 countries. In randomized comparative trials (n = 22), the crude efficacy of AS&AQ was 75.9% (95% CI 74.6–77.1) and the PCR-adjusted efficacy was 93.9% (95% CI 93.2–94.5). The risk (weighted by site) of failure PCR-adjusted of AS&AQ was significantly inferior to non-ACT, superior to dihydroartemisinin-piperaquine (DP, in one Ugandan site), and not different from AS+SP or AL (artemether-lumefantrine). The risk of gametocyte appearance and the carriage rate of AS&AQ was only greater in one Ugandan site compared to AL and DP, and lower compared to non-ACT (p = 0.001, for all comparisons). Anaemia recovery was not different than comparator groups, except in one site in Rwanda where the patients in the DP group had a slower recovery. Conclusion AS&AQ compares well to other treatments and meets the WHO efficacy criteria for use against falciparum malaria in many, but not all, the sub-Saharan African countries where it was studied. Efficacy varies between and within countries. An IPD analysis can inform general and local treatment policies. Ongoing monitoring evaluation is required.

Introduction Rapid access to diagnosis and effective treatment is essential in the drive to roll back malaria. (1) Following the results of multicentre, proof of principle, clinical trials of artesunate [...], Objective To test a novel methodology to define age-based dosing regimens for the treatment of malaria with a new, user-friendly, blister-packaged fixed-dose combination of artesunate and amodiaquine. Methods A weight-for-age reference database of 88 054 individuals from sub-Saharan Africa was compiled using data from Demographic Health Surveys, observational and intervention studies, and standardized for sex, age and malaria risk. We then determined the optimal tablet strength (milligram (mg) per tablet) and age-dose categories for the combination of artesunate and amodiaquine. The proportions of patients predicted to receive doses within newly defined therapeutic ranges for amodiaquine (7-15 mg/kg/day) and artesunate (2-10 mg/kg/day), were estimated for different age categories and mg tablet strengths using models based on the weight-for-age reference database. Findings The optimal paediatric (p) and adult (a) strength tablets contained 25/67.5 and 100/270 mg Artesunate/amodiaquine, respectively. A regimen with five age categories: 0-1 months (1/2 p), 2-11 months (1 p), 1-5 years (2 p), 6-13 years (1 a), and ≥ 14 years (2 a) had an overall dosing accuracy of 83.4% and 99.9% for amodiaquine and artesunate, respectively. Conclusion The proposed method to use weight-for-age reference data from countries where malaria is endemic is a useful tool for designing age-based dosing regimens for antimalarial drugs for drug registration and field use. Bulletin of the World Health Organization 2006;84:956-964. Resume Utilisation de donnees statistiques sur le poids en fonction de l'age pour optimiser le dosage des comprimes et les schemas posologiques pour une nouvelle association artesunate/amodiaquine en proportions fixes, destinee a traiter le paludisme a falciparum Objectif Tester une nouvelle methodologie permettant de definir les schemas posologiques en fonction de l'age pour le traitement du paludisme par une nouvelle association artesunate/amodiaquine en proportions fixes, conditionnee en plaquettes thermoformees et d'usage facile. Methodes Nous avons constitue une base de donnees de reference sur le poids en fonction de l'age a partir de donnees relatives a 88 054 individus, tirees d'Enquetes Demographiques et de Sante et d'etudes d'intervention et standardisees pour l'age, le sexe et le risque de paludisme. Nous avons ensuite determine le dosage optimal des comprimes [milligrammes (mg) par comprime] et les categories de dose par tranche d'age pour l'association artesunate/amodiaquine. Pour les differentes tranches d'age et les differents dosages par comprime, nous avons elabore des previsions estimatives des proportions de malades qui recevront des doses situees dans les plages therapeutiques nouvellement definies pour l'amodiaquine (7 a 15 mg/kg/j) et l'artesunate (2 a 10 mg/kg/j), a partir de modeles utilisant la base de donnees de reference pour le poids en fonction de l'age. Resultats Les dosages optimaux des comprimes a utiliser en pediatrie (p) et chez l'adulte (a) pour l'association artesunate/ amodiaquine etaient respectivement 25/67,5 et 100/270 mg. Un schema therapeutique prevoyant cinq tranches d'age :0-1 mois (1/2 p), 2-11 mois (1 p), 1-5 ans (2 p), 6-13 ans (1 a) et [superieur ou egal a] 14 ans (2 a) presentait une precision posologique globale de 83,4 % pour l'amodiaquine et de 99,9 % pour l'artesunate. Conclusion La methode proposee pour exploiter des donnees de reference sur le poids en fonction de l'age provenant de pays d'endemie palustre fournit un moyen utile a la definition des schemas posologiques en fonction de l'age pour des antipaludiques, en vue de l'homologation et de l'usage sur le terrain de ces medicaments. Resumen Uso del peso para la edad para optimizar la potencia de los comprimidos y la posologia de una nueva combinacion de dosis fijas de artesunato-amodiaquina para tratar la malaria por P. falciparum Objetivo Ensayar una nueva metodologia para definir los regimenes de dosificacion basados en la edad para el tratamiento de la malaria con una nueva combinacion de dosis fijas de artesunato y amodiaquina, facil de usar y suministrada en forma de blisteres. Metodos Se compilo una base de datos de referencia del peso para la edad de 88 054 personas del Africa subsahariana a partir de datos de las Encuestas de Demografia y Salud y estudios observacionales y de intervencion, que se normalizaron en funcion del sexo, la edad y el riesgo de malaria. A partir de ahi se determino la potencia optima de los comprimidos (miligramos (mg) por comprimido) y las categorias de edad-dosis para la combinacion de artesunato y amodiaquina. Utilizando modelos basados en la base de datos de referencia del peso para la edad, se estimaron, para diferentes categorias de edad y potencias (mg) de los comprimidos, las proporciones de pacientes que recibirian dosis situadas dentro de los margenes terapeuticos recien definidos para la amodiaquina (7-15 mg/kg/dia) y el artesunato (2-10 mg/kg/dia). Resultados La potencia optima pediatrica (p) y para adultos (a) de los comprimidos fue de 25/67,5 y 100/270 mg de artesunatol amodiaquina, respectivamente. Un regimen basado en cinco categorias de edad (0-1 meses (1/2 p), 2-11 meses (1 p), 1-5 anos (2 p), 6-13 anos (1 a), y [mayor que o igual a] 14 anos (2 a)) mostro una precision de dosificacion global del 83,4% y 99,9% para la amodiaquina y el artesunato, respectivamente. Conclusiones El metodo propuesto para usar datos de referencia del peso para la edad de los paises con malaria endemica constituye una valiosa herramienta para disenar regimenes de dosificacion basados en la edad para los antimalaricos con miras al registro de medicamentos y a su uso sobre el terreno.

Abstract Background Congo-Brazzaville adopted artemisinin-based combination therapy (ACT) in 2006. Artesunate-amodiaquine (AS + AQ) and artemether-lumefantrine are the first-line and second-line anti-malarial drugs to treat uncomplicated Plasmodium falciparum malaria, respectively. The baseline efficacy of AS + AQ was evaluated from February to August 2005 in patients living in Brazzaville, the capital city of the Republic of Congo. Methods One hundred and ninety-seven patients (96 ≤5 years old and 101 >5 years old, including adults) were recruited in a non-randomized study, treated under supervision with AS + AQ, and were followed up for 28 days in accordance with the 2003 World Health Organization protocol. Plasmodium falciparum recrudescent isolates from day 7 to day 28 were compared to pretreatment isolates by polymerase chain reaction (PCR) to distinguish between re-infection and recrudescence. Results The overall efficacy of AS + AQ after PCR correction on day 28 was 94.4%. An adequate clinical and parasitological response was observed in 94.3% and 94.4% of children aged ≤5 years old and those aged >5 years old (including adults), respectively. The main reported adverse events were dizziness, vomiting, diarrhoea, pruritus, headache, anorexia, and abdominal pain. Conclusion This study has shown the high efficacy of AS + AQ in Congolese patients of all ages with acute uncomplicated falciparum malaria and serves as the baseline efficacy and tolerance of this ACT in Brazzaville.

Abstract Background Knowing the safety profile of anti-malarial treatments in routine use is essential; millions of patients receive now artemisinin combination therapy (ACT) annually, but the return on information through current systems is as yet inadequate. Cohort event monitoring (CEM) is a WHO (World Health Organization)-recommended practice; testing its performance and feasibility in routine practice in malaria-endemic is important. Methods A nine-year CEM-based study of the safety of artesunate-amodiaquine (ASAQ) at five peripheral health facilities in a rural district of South-western Senegal. Staff (nurses, health workers) were trained to collect actively and systematically information on the patient, treatment and events on a purposely designed questionnaire. The occurrence and severity of events was collected before, during and after treatment up to 28 days in order to generate information on all adverse events (AEs) as well as treatment-emerging signs/symptoms (TESS). Laboratory tests (haematology, liver and renal) was planned for at least 10% of cases. Results During 2001–2009, 3,708 parasitologically-confirmed malaria cases (mean age = 16.0 ± 12.7 years) were enrolled (26% and 52% of all and parasitologically-confirmed ASAQ treatments, respectively). Treatment was supervised in 96% of cases. Products changed over time: 49% were a loose combination of individually-packaged products (available 2001–03), 42% co-blistered products (2004–09) and 9% a fixed-dose co-formulation (2006–09); dosing was age-based for 42%, weight-based for 58%. AS and AQ were correctly dosed in 97% and 82% of cases with the loose and 93% and 86% with the fixed combination, but only 50% and 42% with the co-blistered product. Thirty-three per cent (33%) of patients had at least one sign/symptom pre-treatment, 12% had at least one AE and 9% a TESS (total events 3,914, 1,144 and 693, respectively). AEs overestimated TESS by 1.2-2 fold (average 1.7). Changes in laboratory value were insignificant. Over-dosing more than doubled the risk of TESS, though statistical significance was reached only during 2003–2007. The incidence of serious events (including death) was five per thousand. Conclusions The study was successful in quantifying and characterizing known reactions and has benchmarking value. Health staff performance varied. Investments in training, motivating and providing a quality control system would be needed. The study proved that a CEM-based system is feasible in this setting but more research is needed to assess whether it is sustainable and what conditions would make it cost-effective, including the amount and quality of data generated, and the use thereof for decision-making.

Abstract Background Malaria is reportedly receding in different epidemiological settings, but local long-term surveys are limited. At Mlomp dispensary in south-western Senegal, an area of moderate malaria transmission, year-round, clinically-suspected malaria was treated with monotherapy as per WHO and national policy in the 1990s. Since 2000, there has been a staggered deployment of artesunate-amodiaquine after parasitological confirmation; this was adopted nationally in 2006. Methods Data were extracted from clinic registers for the period between January 1996 and December 2010, analysed and modelled. Results Over the 15-year study period, the risk of malaria decreased about 32-times (from 0.4 to 0.012 episodes person-year), while anti-malarial treatments decreased 13-times (from 0.9 to 0.07 treatments person-year) and consultations for fever decreased 3-times (from 1.8 to 0.6 visits person-year). This was paralleled by changes in the age profile of malaria patients so that the risk of malaria is now almost uniformly distributed throughout life, while in the past malaria used to concern more children below 16 years of age. Conclusions This study provides direct evidence of malaria risk receding between 1996-2010 and becoming equal throughout life where transmission used to be moderate. Infection rates are no longer enough to sustain immunity. Temporally, this coincides with deploying artemisinin combinations on parasitological confirmation, but other contributing causes are unclear.

Abstract Background Artesunate and amodiaquine (AS&AQ) is at present the world's second most widely used artemisinin-based combination therapy (ACT). It was necessary to evaluate the efficacy of ACT, recently adopted by the World Health Organization (WHO) and deployed over 80 countries, in order to make an evidence-based drug policy. Methods An individual patient data (IPD) analysis was conducted on efficacy outcomes in 26 clinical studies in sub-Saharan Africa using the WHO protocol with similar primary and secondary endpoints. Results A total of 11,700 patients (75% under 5 years old), from 33 different sites in 16 countries were followed for 28 days. Loss to follow-up was 4.9% (575/11,700). AS&AQ was given to 5,897 patients. Of these, 82% (4,826/5,897) were included in randomized comparative trials with polymerase chain reaction (PCR) genotyping results and compared to 5,413 patients (half receiving an ACT). AS&AQ and other ACT comparators resulted in rapid clearance of fever and parasitaemia, superior to non-ACT. Using survival analysis on a modified intent-to-treat population, the Day 28 PCR-adjusted efficacy of AS&AQ was greater than 90% (the WHO cut-off) in 11/16 countries. In randomized comparative trials (n = 22), the crude efficacy of AS&AQ was 75.9% (95% CI 74.6–77.1) and the PCR-adjusted efficacy was 93.9% (95% CI 93.2–94.5). The risk (weighted by site) of failure PCR-adjusted of AS&AQ was significantly inferior to non-ACT, superior to dihydroartemisinin-piperaquine (DP, in one Ugandan site), and not different from AS+SP or AL (artemether-lumefantrine). The risk of gametocyte appearance and the carriage rate of AS&AQ was only greater in one Ugandan site compared to AL and DP, and lower compared to non-ACT (p = 0.001, for all comparisons). Anaemia recovery was not different than comparator groups, except in one site in Rwanda where the patients in the DP group had a slower recovery. Conclusion AS&AQ compares well to other treatments and meets the WHO efficacy criteria for use against falciparum malaria in many, but not all, the sub-Saharan African countries where it was studied. Efficacy varies between and within countries. An IPD analysis can inform general and local treatment policies. Ongoing monitoring evaluation is required.

Abstract Background The use of artemisinin derivative-based combination therapy (ACT) such as artesunate plus amodiaquine is currently recommended for the treatment of uncomplicated Plasmodium falciparum malaria. Fixed-dose combinations are more adapted to patients than regimens involving multiple tablets and improve treatment compliance. A fixed-dose combination of artesunate + amodiaquine (ASAQ) was recently developed. To assess the efficacy and safety of this new combination and to define its optimum dosage regimen (once or twice daily) in the treatment of uncomplicated P. falciparum malaria, a multicentre clinical study was conducted. Methods A multicentre, randomized, controlled, investigator-blinded, parallel-group study was conducted in five African centers in Cameroon, Madagascar, Mali and Senegal from March to December 2006. Efficacy and safety of ASAQ were assessed compared to those of artemether + lumefantrine (AL). The WHO protocol with a 28-day follow-up for assessing the drug therapeutic efficacy was used. Patients suffering from uncomplicated P. falciparum malaria were randomized to receive ASAQ orally once daily (ASAQ1), ASAQ twice daily (ASAQ2) or AL twice daily (AL) for three days. The primary outcome was PCR-corrected parasitological cure rate and clinical response. Results Of 941 patients initially randomized and stratified into two age groups ( Conclusion The non-inferiority of ASAQ compared with AL was demonstrated. The fixed-dose combination artesunate + amodiaquine (ASAQ) is safe and efficacious even in young children under 5 years of age. Whilst administration on a twice-a-day basis does not improve the efficacy of ASAQ significantly, a once-a-day intake of this new combination clearly appears as an effective and safe therapy in the treatment of uncomplicated P. falciparum malaria both in adults and children. Implications of such findings are of primary importance in terms of public health especially in African countries. As most national policies plan to strengthen malaria control to reach the elimination of this disease, anti-malarial drugs such as the artesunate + amodiaquine fixed-dose ACT will play a pivotal role in this process. Trial registration The protocol was registered with the www.clinicaltrials.gov open clinical trial registry under the identifier number NCT00316329.

Abstract Background Intermittent preventive treatment with sulphadoxine-pyrimethamine (SP) is recommended for reducing the risk of malaria in pregnancy and its consequences on mothers and babies (IPTp-SP). Indicators of implementation and effects of IPTp-SP were collected in a rural clinic in Southern Senegal. Methods Women seen routinely at the antenatal clinic (ANC) of a rural dispensary during 2000–2007. Deployment of IPTp-SP started in January 2004. Inspection of antenatal and outpatient clinic registries of the corresponding period. Results Between 1st January 2000 and 30th April 2007, 1,781 women of all gravitidities and parities attended the ANC with 965 deliveries (606 and 398 respectively since 1st January 2004, when IPTp-SP was started.) 69% of women were seen ≥ 3 times; 95% received at least one dose and 70% two doses of SP (from 61% in 2004 to 86% in 2007). The first visit, first and second dose of SP occurred at a median week 20, 22 and 31. The probability of receiving two doses was > 80% with ≥ 3 antenatal visits and a first dose of SP by week 20. The prevalence of maternal malaria was low and similar pre- (0.7%) and during IPTp (0.8%). Effects on of low birth weight (LBW, < 2.5 kg) were non-statistically significant. The prevalence of LBW was 10.8% pre- and 7.7% during IPTp deployment (29% risk reduction, p = 0.12). Unfavourable pregnancy outcomes numbered 72 (7.5% of pregnancies with known outcome), including 30 abortions and 42 later deaths (late foetal deaths, stillbirth, peri-natal) of which 13 with one or more malformations (1.35% of all recorded deliveries). Conclusion The implementation of IPTp-SP was high. Early attendance to ANC favours completion of IPTp-SP. The record keeping system in place is amenable to data extraction and linkage. A model was developed that predicts optimal compliance to two SP doses, and could be tested in other settings. Maternal malaria was infrequent and unaffected by IPTp-SP. The risk of LBW was lower during IPT implementation but the difference was non-significant and could have other explanations.

Abstract Background There are no data on the long term use of an artemisinin combination treatment in moderate or high transmission areas of Africa. Methods and findings Artesunate plus amodiaquine (AS+AQ) was used to treat slide-proven Plasmodium falciparum-infected patients of all ages in the Oussouye district, Casamance, Senegal, over a period of six years (2000 to 2005). Efficacy, by Kaplan Meier survival analysis (n = 966), and safety (adverse event rates, n = 752) were determined over 28 days. A weight-based dosing regimen was used for the loose tablets during 2000–2003 (n = 731) and a commercially available co-blister was used during 2004–2005 (n = 235). Annual crude (non PCR corrected) rates remained stable over the study period [range 88.5–96.7%; overall 94.6 (95% CI 92.9–95.9)]. Nine co-blister treated patients (0.9%) withdrew because of drug-related adverse events; seven had gastrointestinal complaints of whom two were hospitalized for vomiting. By Day 28, the mean total bilirubin (n = 72), AST (n = 94) and ALT (n = 95) values decreased. Three patients had Day 28 AST/ALT values > 40 < 200 IU/L. Changes in white cell counts were unremarkable (n = 87). Conclusion AS+AQ in combination was highly efficacious and well-tolerated in this area and justifies the decision to use it as first line treatment. Long-term monitoring of safety and efficacy should continue.