View clinical trials related to Vivax Malaria.
Filter by:A clinical study to assess the safety and efficacy of alternative regimens of primaquine for radical cure of vivax malaria in glucose 6-phosphate dehydrogenase (G6PD) deficient. G6PD deficient patients with P. vivax monoinfection will be treated with either weekly or delayed one-week course of primaquine, and the currently recommended by national guideline, 12-week chloroquine regimen to compare treatment safety among groups. All groups will be actively monitored for hemolysis during treatment and will have six-month follow-up period to assess treatment efficacy.
This will be a single-arm observational cohort study. Malaria patients with Plasmodium vivax and meeting study inclusion criteria, who give consent to be enrolled in the study, will have their G6PD status measured by the CareStart™ G6DP rapid diagnostic test (G6PD RDT), and primaquine prescribed according to the result. According to the G6PD RDT result, primaquine will be prescribed at 0.25mg/kg/day for 14 days (normal patients) or 0.75mg/kg weekly for eight weeks (deficient patients). All will receive treatment with chloroquine to clear asexual stages of infection. Patients will be reviewed at day 2, day 7 and day 14. At these visits patients will undergo a brief clinical assessment and a small blood sample will be taken for repeat haemoglobin measurement and dried blood spot for carboxyprimaquine measurement (day 7 and day 14 only). In general, antimalarial treatment will be unsupervised to reflect field conditions. However a subset of 25 G6PD normal patients at a single site will have each day of their primaquine treatment administered and observed at the treatment centre. This is to determine a calibration curve for primaquine pharmacokinetic studies. Dried blood spots will be stored appropriately. Day zero samples will be genotyped in Bangkok (MORU, Dr. Mallika Imwong) after DNA extraction. PCR-RFLP will be used to detect the allele associated with the Mediterranean variant of G6PD deficiency. In addition DNA extracts will be sent for more systematic genetic testing for known G6PD variants through existing collaborations with the Wellcome Trust Sanger Institute. The day 7 and 14 dried blood spot samples will be analysed in the MORU pharmacology laboratory for primaquine and carboxyprimaquine concentrations, from which adherence to primaquine can be determined retrospectively, using the subset of 25 patients receiving directly observed therapy to calibrate the results. Funder: WellcomeTrust, Grant reference: 107548/Z/15/Z
Feasibility of methylene blue-based combination therapy in the radical treatment of adult patients with Plasmodium vivax malaria in Ethiopia: a randomised controlled pilot trial Study rationale: Elimination has become the goal of malaria programmes in an increasing number of endemic countries and regions. Primaquine (PQ) is the only registered drug for radical cure of Plasmodium vivax malaria. Prolonged PQ-based combination therapy carries safety concerns and resistance to chloroquine (CQ) and PQ is emerging. Methylene blue (MB) has recently been shown to be safe and effective in the treatment of Plasmodium falciparum malaria in West Africa. As there is evidence for MB probably being effective against the hypnozoites of Plasmodium vivax, MB-based drug regimens could be an alternative to PQ-based combination therapy in Plasmodium vivax malaria. Study objectives: The main objective of this trial is to study the feasibility of MB-based combination therapy in patients with uncomplicated P. vivax malaria in an endemic area of Ethiopia.
The investigators propose to leverage the unique infrastructures and expertise of National Centre for Parasitology Entomology and Malaria Control and the Pasteur Institute in Cambodia and combine modern fieldwork, including a mobile laboratory fully equipped for molecular biology and culture experiments, with state-of-the-art genomic analyses to investigate how Plasmodium vivax parasites respond to antimalarial drugs. The investigators will focus on resistance to CQ, the choice treatment for vivax malaria in most endemic countries, for which treatment failures have been reported in Cambodia. The study will address some of the key biological mechanisms limiting the efficiency of drug therapy in P. vivax, including the identification of genetic polymorphisms underlying drug resistance in Cambodian P. vivax. The findings will provide a first unbiased perspective on the mechanisms of drug resistance in P. vivax and have the strong potential to significantly improve malaria control in Southeast Asia.
The weight of malaria falls most heavily on young children and pregnant women but studies of the safety of antimalarials in pregnancy and lactation are few. The only recommended medication used for radical treatment of P.vivax is primaquine. The 2010 WHO malaria guidelines recommend its use in all patients with P.vivax infection in areas of low transmission, in the absence of contraindications. Primaquine is contraindicated in pregnancy. The postpartum period presents a key opportunity to definitively treat women who suffer multiple malaria relapses during pregnancy. The 2010 WHO malaria treatment guidelines allow for primaquine use during lactation but there are no studies to date quantifying primaquine excretion in breast milk and the dose that breastfed infants would be exposed to is unknown. The investigators propose to study the pharmacokinetics of primaquine in maternal and infant plasma and in breast milk during a 14 day radical treatment of P.vivax. Some inferences about the expected behavior of primaquine in lactation can be drawn from its known pharmacologic properties. Primaquine pharmacokinetics have been well characterized in healthy subjects and malaria patients after single and multiple oral dosing. Peak concentrations are reached within 2-3 hours after dosing and the plasma elimination half-life is ~7 hours. It is extensively distributed in the tissue and largely metabolized to inert carboxyprimaquine, the major plasma metabolite, which undergoes further biotransformation to unknown metabolites that are probably more toxic than the parent compound. The identification of other metabolites in humans has been difficult to pursue because the expected aminophenol metabolites are unstable. No pharmacokinetic studies have been done to measure primaquine excretion in breast milk. A few studies have been done of other antimalarials during lactation and have shown low levels of drug in breast milk during treatment.
This research is intended to study the efficacy of chloroquine (CQ) and primaquine (PQ) for Plasmodium vivax (P.vivax) infection, and also to study the recurrence rate among patients with P.vivax malaria on standard doses of CQ and PQ. For this study, PQ will be withheld for 28 days so as to study the efficacy of CQ alone. This study will assess whether CQ is still effective against P.vivax or whether there are resistant P.vivax strains in Bhutan.
In Southeast Asia, Plasmodium vivax (Pv) infection reaches 50-80% and bears a greater burden of disease than Plasmodium falciparum (Pf). As control over Pf improves, Pv will assume increasingly larger percentages of malaria prevalence. The chronicity of Pv, due to the latent liver stage (hypnozoite) not eradicated by chloroquine, causes recurring disability and compounds the economic burden of those with symptomatic disease. The only widely available treatment for hypnozoites is primaquine, which, because of challenges with tolerability, safety in G6PD deficient persons, and compliance, is not commonly prescribed for the treatment of Pv. Currently, chloroquine is used for the treatment of the blood stages of Pv, however, there are concerns about increasing parasite resistance. Alternative treatments, such as artesunate, should be considered in the future of the treatment of blood stage Pv. The use of primaquine in the treatment of hypnozoites (radical cure) should be emphasized so that transmission of Pv can be controlled. This study aims to determine the optimal primaquine regimen for radical cure of Plasmodium vivax. Chloroquine is currently the standard of treatment for Plasmodium vivax. Chloroquine may have synergistic effects when used with primaquine and due to its long half-life may delay the first relapse of vivax malaria. In contrast, artesunate does not have documented interactions with primaquine and has a very short half-life, thus, presumably will have no impact on first relapse. Combining primaquine with these two anti-malarials may lead to an alternative regimen for Pv infection and changing the primaquine dosing regimen may lead to a more practical and efficacious therapy.
The cure rate of artemether/lumefantrine in the treatment of vivax malaria.
For the treatment of P.vivax the standard treatment is chloroquine. There is a growing body of evidence suggesting that pregnant women may require different doses of drugs, including antimalarials due to the physiological changes of pregnancy. It is important that any drug used in pregnant women it is given at the correct dose. The only way to evaluate this is by pharmacokinetic studies. The investigators propose to evaluate the pharmacokinetics of chloroquine when use to treat P.vivax in the 2nd or 3rd trimester of pregnancy. The same evaluation in the same woman post-partum is required as a control.
This randomized clinical trial will be conducted in subjects with uncomplicated Plasmodium vivax malaria during November 2010 to March 2012. The aim of the study is to compare the efficacy and safety of artesunate-amodiaquine plus primaquine (AS-AQ + PQ) and dihydroartemisinin-piperaquine plus primaquine (DHP + PQ) in uncomplicated vivax malaria. The significance of the study is to find alternative drug for treating patients with vivax malaria in case the standard treatment is not available or become resistance. This study will give thorough information about the efficacy and safety of 2 artemisinin-based combination therapies (ACTs) in combination with primaquine. It will also inform the Indonesian Ministry of Health on their suggested policies for radical cure of vivax malaria, and provides evidence based treatment options for chloroquine resistant vivax malaria. This study will also provide information about prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and G6PD variants in North Sumatera population.