Dataset Information

Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in Amazon basin communities.

ABSTRACT:

Background

Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS) and mefloquine (MQ) combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance.

Methods

The effectiveness of a fixed-dose combination of AS and MQ (ASMQ) in reducing malaria transmission was tested in isolated communities of the Juruá valley in the Amazon region.Priority municipalities within the Brazilian Legal Amazon area were selected according to pre-specified criteria. Routine national malaria control programmatic procedures were followed. Existing health structures were reinforced and health care workers were trained to treat with ASMQ all confirmed falciparum malaria cases that match inclusion criteria. A local pharmacovigilance structure was implemented. Incidence of malaria and hospitalizations were recorded two years before, during, and after the fixed-dose ASMQ intervention. In total, between July 2006 and December 2008, 23,845 patients received ASMQ. Two statistical modelling approaches were applied to monthly time series of P. falciparum malaria incidence rates, P. falciparum/Plasmodium vivax infection ratio, and malaria hospital admissions rates. All the time series ranged from January 2004 to December 2008, whilst the intervention period span from July 2006 to December 2008.

Results

The ASMQ intervention had a highly significant impact on the mean level of each time series, adjusted for trend and season, of 0.34 (95% CI 0.20 - 0.58) for the P. falciparum malaria incidence rates, 0.67 (95% CI 0.50 - 0.89) for the P. falciparum/P. vivax infection ratio, and 0.53 (95% CI 0.41 - 0.69) for the hospital admission rates. There was also a significant change in the seasonal (or monthly) pattern of the time series before and after intervention, with the elimination of the malaria seasonal peak in the rainy months of the years following the introduction of ASMQ. No serious adverse events relating to the use of fixed-dose ASMQ were reported.

Conclusions

In the remote region of the Juruá valley, the early detection of malaria by health care workers and treatment with fixed-dose ASMQ was feasible and efficacious, and significantly reduced the incidence and morbidity of P. falciparum malaria.

SUBMITTER: Santelli AC

PROVIDER: S-EPMC3472241 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature

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Publications

Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in Amazon basin communities.

Santelli Ana C AC Ribeiro Isabela I Daher André A Boulos Marcos M Marchesini Paola B PB dos Santos Roseli La Corte RL Lucena Marize B F MB Magalhães Izanelda I Leon Antonio P AP Junger Washington W Ladislau José L B JL

Malaria journal 20120820

<h4>Background</h4>Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS) and mefloquine (MQ) combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance.<h4>Methods</h4>The effectiveness of a fixed-dose combination of AS and MQ (ASMQ) in reducing malaria transmission was tested in isolated communities of the Juruá valley in the Amazon region.Priority municipalities within the Brazilian Legal Ama ...[more]

PMID: 22905900

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Project description:BACKGROUND:The World Health Organization (WHO) recommends combinations of an artemisinin derivative plus an anti-malarial drug of longer half-life as treatment options for uncomplicated Plasmodium falciparum infections. In Africa, artesunate-mefloquine (ASMQ) is an infrequently used artemisinin-based combination therapy (ACT) because of perceived poor tolerance to mefloquine. However, the WHO has recommended reconsideration of the use of ASMQ in Africa. In this large clinical study, the pharmacokinetics (PK) of a fixed dose combination of ASMQ was investigated in an African paediatric population to support dosing recommendations used in Southeast Asia and South America. METHODS:Among the 472 paediatric patients aged 6-59 months from six African centres included in the large clinical trial, a subset of 50 Kenyan children underwent intensive sampling to develop AS, its metabolite dihydroartemisinin (DHA) and MQ PK models. The final MQ PK model was validated using sparse data collected in the remaining participants (NONMEM®). The doses were one or two tablets containing 25/55 mg AS/MQ administered once a day for 3 days according to patients' age. A sensitive LC-MS/MS method was used to quantify AS, DHA and MQ concentrations in plasma. An attempt was made to investigate the relationship between the absence/presence of malaria recrudescence and MQ area under the curve (AUC) using logistic regression. RESULTS:AS/DHA concentration-time profiles were best described using a one-compartment model for both compounds with irreversible AS conversion into DHA. AS/DHA PK were characterized by a significant degree of variability. Body weight affected DHA PK parameters. MQ PK was characterized by a two-compartment model and a large degree of variability. Allometric scaling of MQ clearances and volumes of distribution was used to depict the relationship between MQ PK and body weight. No association was found between the model predicted AUC and appearance of recrudescence. CONCLUSIONS:The population pharmacokinetic models developed for both AS/DHA and MQ showed a large variability in drug exposure in the investigated African paediatric population. The largest contributor to this variability was body weight, which is accommodated for by the ASMQ fixed dose combination (FDC) dosing recommendation. Besides body weight considerations, there is no indication that the dosage should be modified in children with malaria compared to adults. Trial registration Pan African Clinical Trials Registry PACTR201202000278282 registration date 2011/02/16.

Project description:BackgroundDeclining in susceptibility of Plasmodium falciparum to mefloquine is reported in South-East Asia. A revisiting on mefloquine pharmacokinetics-pharmacodynamics (PK/PD) could assist in finding new appropriate dosage regimens in combination with artesunate as a three-day course treatment.ObjectiveThis study aimed to investigate promising alternative artesunate-mefloquine combination regimens that are effective for the treatment of patients with mefloquine-sensitive and resistant P. falciparum malaria.MethodsData collected during 2008-2009 from 124 patients with uncomplicated P. falciparum malaria were included in the analysis, 90 and 34 patients with sensitive and recrudescence response, respectively. All patients were treated with a three-day combination of artesunate-mefloquine. Population PK-PD models were developed. The developed models were validated with clinically observed data. Simulations of clinical efficacy of alternative mefloquine regimens were performed based on mefloquine sensitivity, patients' adherence and parasite biomass.ResultsThe developed PK/PD models well described with clinically observed data. For mefloquine-resistant P. falciparum, a three-day standard regimen of artesunate-mefloquine is suitable (>50% efficacy) only when the level of parasite sensitivity was < 1.5-fold of the cut-off level (IC50 < 36 nM). For mefloquine-sensitive parasite with IC50 < 23.19 nM (0.96-fold), all regimens provided satisfactory efficacy. In the isolates with IC50 of 24 nM, regimen-I is recommended. Curative treatment criteria for mefloquine and artesunate were C336h (>408 ng.mL-1) or Cmax/IC50 (>130.1 g.m/M), and Cmax/IC50 (>381.2 g.m/M), respectively.ConclusionsClinical use of a three-day standard artesunate-mefloquine is suitable only when the IC50 of P. falciparum isolates is lower than 36 nM. Otherwise, other ACT regimens should be replaced. For mefloquine-sensitive parasite, a dose reduction is recommended with the IC50 is lower than 23.19 nM.

Project description:BackgroundSeveral studies have demonstrated the efficacy of artemisinin-combination therapy (ACT) across malaria zones of the world. Fixed dose ACT with shorter courses and fewer tablets may be key determinants to ease of administration and compliance.MethodsChildren aged one year to 13 years presenting with uncomplicated Plasmodium falciparum malaria were recruited in Ibadan, south-western Nigeria. A total of 250 children each were randomly assigned to receive three doses of artesunate/sulphamethoxypyrazine/pyrimethamine (AS + SMP) (12 hourly doses over 24 hours) or three doses of artesunate/amodiaquine (AS + AQ) (daily doses over 48 hours). Efficacy and safety of the two drugs were assessed using a 28-day follow-up and the primary outcome was PCR- corrected parasitological cure rate and clinical response.ResultsThere were two (0.4%) early treatment failures, one in each treatment arm. The PCR corrected cure rates for day 28 was 97.9% in the AS + AQ arm and 95.6% in the AS + SMP arm (p = 0.15). The re-infection rate was 1.7% in the AS + AQ arm and 5.7% in the AS + SMP arm (p = 0.021). The fever clearance time was similar in the two treatment groups: 1 - 2 days for both AS + SMP and AS + AQ (p = 0.271). The parasite clearance time was also similar in the two treatment groups with 1 - 7 days for AS + SMP and 1 - 4 days for AS + AQ (p = 0.941). The proportion of children with gametocytes over the follow-up period was similar in both treatment groups. Serious Adverse Events were not reported in any of the patients and in all children, laboratory values (packed cell volume, liver enzymes, bilirubin) remained within normal levels during the follow-up period but the packed cell volume was significantly lower in the AS + SMP group.ConclusionsThis study demonstrates that AS + SMP FDC given as three doses over 24 hours (12-hour intervals) has similar efficacy as AS + AQ FDC given as three doses over 48 hours (24-hour interval) for the treatment of uncomplicated Plasmodium falciparum malaria in children in Nigeria. Both drugs also proved to be safe. Therefore, AS + SMP could be an alternative to currently recommended first-line ACT with continuous resistance surveillance.

Project description:BackgroundArtemisinin-based combination therapy (ACT) is recommended as a means of prolonging the effectiveness of first-line malaria treatment regimens. Different brands of mefloquine (MQ) have been reported to be non-bioequivalent; this could result in sub-therapeutic levels of mefloquine with decreased efficacy. In 2002, mefloquine-artesunate (MQ-AS) combination therapy was adopted as the first-line treatment for uncomplicated Plasmodium falciparum malaria in the Amazon region of Peru. Although MQ resistance has yet to be reported from the Peruvian Amazon, it has been reported from other countries in the Amazon Region. Therefore, continuous monitoring is warranted to ensure that the first-line therapy remains efficacious. This study examines the in vivo efficacy and pharmacokinetic parameters through Day 56 of three commercial formulations of MQ (Lariam, Mephaquin, and Mefloquina-AC Farma) given in combination with artesunate.MethodsThirty-nine non-pregnant adults with P. falciparum mono-infection were randomly assigned to receive artesunate in combination with either (1) Lariam, (2) Mephaquin, or (3) Mefloquina AC. Patients were assessed on Day 0 (with blood samples for pharmacokinetics at 0, 2, 4, and 8 hours), 1, 2, 3, 7, and then weekly until day 56. Clinical and parasitological outcomes were based on the standardized WHO protocol.Whole blood mefloquine concentrations were determined by high-performance liquid chromatography and pharmacokinetic parameters were determined using non-compartmental analysis of concentration versus time data.ResultsBy day 3, all patients had cleared parasitaemia except for one patient in the AC Farma arm; this patient cleared by day 4. No recurrences of parasitaemia were seen in any of the 34 patients. All three MQ formulations had a terminal half-life of 14-15 days and time to maximum plasma concentration of 45-52 hours. The maximal concentration (Cmax) and interquartile range was 2,820 ng/ml (2,614-3,108) for Lariam, 2,500 ng/ml (2,363-2,713) for Mephaquin, and 2,750 ng/ml (2,550-3,000) for Mefloquina AC Farma. The pharmacokinetics of the three formulations were generally similar, with the exception of the Cmax of Mephaquin which was significantly different to that of Lariam (p = 0.04).ConclusionAll three formulations had similar pharmacokinetics; in addition, the pharmacokinetics seen in this Peruvian population were similar to reports from other ethnic groups. All patients rapidly cleared their parasitaemia with no evidence of recrudescence by Day 56. Continued surveillance is needed to ensure that patients continue to receive optimal therapy.

Project description:BackgroundPharmacokinetic (PK) and pharmacodynamic (PD) data are limited for artesunate (AS) and amodiaquine (AQ) in uncomplicated Plasmodium falciparum.MethodsFrom 2007-8, 54 P. falciparum-infected, Kenyan adults were assigned randomly fixed dose (FD) ASAQ (n?=?26) or non-fixed (NF) ASAQ (n?=?28). Total doses were 600 mg AS (both arms) + 1,620 mg (FD) or 1,836 mg (NF)AQ. Follow-up extended over 28 days. PK data were collected for AS, dihydroartemisinin (DHA), AS + DHA combined as DHA equivalents (DHAeq), AQ, desethylamodiaquine (DAQ),and their relationships assessed against the PD collected data consisting of parasitological efficacy, adverse events (AEs), and the Bazett's corrected QTinterval (QTcB).ResultsMean AUC 0-72 of dihydroartemisinin equivalents (DHAeq) when administered as a fixed dose (FD) compared to NF dose were similar: 24.2 ±4.6 vs 26.4±6.9 µmol*h/L (p?=?0.68) Parasite clearance rates were also similar after 24 hrs: 17/25 (68%) vs 18/28(64.3%) (p?=?0.86),as well as at 48 hrs: 25/8 (100%)vs 26 (92.9%)/28 (p?=?0.49). Mean FD vs NF DAQ AUC0-28 were 27.6±3.19 vs 32.7±5.53 mg*h/L (p?=?0.0005). Two PCR-proven new infections occurred on Day (D) 28 for estimated, in vivo, DAQ minimum inhibitory concentrations of 15.2 and 27.5 ng/mL. Combining the FD and NF arms, the mean QTcB at D2+4 hrs increased significantly (p?=?0.0059) vs baseline: 420 vs410 ms (??=?9.02 (95% confidence interval 2.72-15.31 ms), explained by falling heart rates, increasing DAQ concentrations and female sex in a general linear mixed effects model. Ten of 108 (9.26%) AEs (5/arm) reported by 37/54 (68.5%) patients were possibly or probably drug related. Severe, asymptomatic neutropaenia developed in 2/47 (4.25%) patients on D28: 574/µL (vsD0: 5,075/µL), and 777/µL (vsD0: 3,778/µL).ConclusionsTolerability of both formulations was good. For QTcB, a parameter for ECG modifications, increases were modest and due to rising DAQ concentrations and falling heart rates as malaria resolved. Rapid parasite clearance rates and no resistant infections suggest effective pharmacokinetics of both formulations.

Dataset Information

Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in Amazon basin communities.

Background

Methods

Results

Conclusions

Publications

Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in Amazon basin communities.

Similar Datasets

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