Study on the Treatment of Vivax Malaria (VHX)
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ClinicalTrials.gov Identifier: NCT01074905 |
Recruitment Status :
Completed
First Posted : February 24, 2010
Last Update Posted : August 28, 2013
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Condition or disease | Intervention/treatment | Phase |
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Vivax Malaria | Drug: Artesunate Drug: Chloroquine Drug: Chloroquine/Primaquine | Phase 3 |
Considerably less attention has been paid to Plasmodium vivax epidemiology than Plasmodium falciparum. In areas of relatively low unstable transmission, which comprise the majority of P.vivax affected areas, vivax malaria is predominantly a disease of children (Luxemburger et al 1999). Chloroquine has long been the standard treatment for vivax malaria. Primaquine is recommended for radical cure of vivax malaria, but is difficult to administer due to dosing duration and side effects.
This study aims to characterize the epidemiologic history comparing the efficacy of 3 antimalarial regimens (chloroquine, artesunate, and chloroquine/primaquine) for plasmodium vivax in western Thailand. Chloroquine is currently the standard of treatment for Plasmodium vivax. Due to the long half-life or chloroquine, the first relapse of vivax malaria may be delayed. In contrast, artesunate has a very short half-life, thus, having no impact on first relapse. It is not known whether chloroquine reduces the overall number of relapses, or only delays the first relapse. There are many important questions about the biology of vivax malaria of relevance to treatment that remain unanswered. For example is the number of relapses per infection (i.e. per successful inoculation) predetermined or adaptive? If it is predetermined then suppression of the first relapse (as with chloroquine, mefloquine or piperaquine) will reduce the total number of relapses and this is a clear benefit. If it is adaptive then these drugs will simply delay the relapses and there is less clear benefit. These various uncertainties illustrate the importance of detailed comparative longitudinal evaluations. In order to characterize the biology of vivax malaria, it will be necessary to compare regimens with and without primaquine. Because of the challenges that face primaquine prescription (side effects, toxicity in G6PD deficient patients and duration of treatment), it is not commonly deployed along the Thai Burma border. In effect, we will be comparing usual practice (non primaquine regimens) with the recommended WHO and Thai MOPH practice (use of primaquine for 14 days). The information we will gather is crucial to the understanding of chloroquine and its effect on the vivax parasite. This will lead to future studies and invariably change the way we treat vivax malaria.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 655 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A Randomised Open Label Study Comparing the Efficacy of Chloroquine/Primaquine, Chloroquine and Artesunate in the Treatment of Vivax Malaria Along the Thai-Burmese Border |
Study Start Date : | May 2010 |
Actual Primary Completion Date : | October 2012 |
Actual Study Completion Date : | October 2012 |

Arm | Intervention/treatment |
---|---|
Active Comparator: Artesunate
2 mg/kg/day as single daily dose given for 5 days; maximum dose range is 1.6 to 2.4 mg/kg/day or a total of 8 to 12 mg/kg.
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Drug: Artesunate
2 mg/kg/day as single daily dose given for 5 days; maximum dose range is 1.6 to 2.4 mg/kg/day or a total of 8 to 12 mg/kg. |
Active Comparator: Chloroquine
25 mg base/kg given in divided doses (10,10,5) over 3 days; Absolute range 20-30 mg/kg.
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Drug: Chloroquine
25 mg base/kg given in divided doses (10,10,5) over 3 days; Absolute range 20-30 mg/kg. |
Experimental: Chloroquine/Primaquine
Chloroquine 3 days and Primaquine 14 days
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Drug: Chloroquine/Primaquine
Chloroquine 3 days and Primaquine 14 days |
- The first recurrence of Plasmodium vivax malaria [ Time Frame: Day 28 ]The first recurrence of Plasmodium vivax malaria within 28 days
- Any recurrence of Plasmodium vivax parasitemia [ Time Frame: 1 year ]Any recurrence of Plasmodium vivax parasitemia within the follow up period
- Time to first recurrence, median time between episodes of vivax infections and total number of episodes [ Time Frame: 1 year ]Time to first recurrence, median time between episodes of vivax infections and total number of episodes in the follow up period
- Overall number of days of illness and haematocrit below 30% [ Time Frame: 1 year ]Overall number of days of illness and haematocrit below 30% within the follow up period
- Chloroquine level [ Time Frame: Day 7 ]Whole blood chloroquine level at day 7 and any day of recurrence of Plasmodium vivax malaria
- Adverse events [ Time Frame: 1 year ]Adverse event profiles of artesunate, chloroquine and primaquine

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Ages Eligible for Study: | 6 Months and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Adults and children > 6 months
- Weight > 7 kg for children
- Have not had primaquine since last Pv episode
- Participant (or parent/guardian if < 18 years old) is willing and able to give written informed consent
- Microscopic diagnosis of Plasmodium vivax mono-infection
- Ability (in the investigators opinion) and willingness of patient or parent/guardian to comply with all study requirements
Exclusion Criteria
- Allergy to artesunate, chloroquine or primaquine
- Severe malaria
- Patients with microscopic diagnosis of co-infection with Plasmodium falciparum
- Presence of any condition which in the judgement of the investigator would place the subject at undue risk or interfere with the results of the study
- Inability to tolerate oral medication
- Pregnancy
- Blood transfusion in the last 3 months
- Antimalarial in last 2 months

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01074905
Thailand | |
Shoklo Malaria Research Unit | |
Mae Sot, Thailand |
Principal Investigator: | Francois Nosten, MD | Shoklo Malaria Research Unit |
Responsible Party: | University of Oxford |
ClinicalTrials.gov Identifier: | NCT01074905 |
Other Study ID Numbers: |
SMRU0908 |
First Posted: | February 24, 2010 Key Record Dates |
Last Update Posted: | August 28, 2013 |
Last Verified: | August 2013 |
vivax malaria artesunate chloroquine primaquine relapse |
Malaria Malaria, Vivax Protozoan Infections Parasitic Diseases Infections Vector Borne Diseases Artesunate Chloroquine Chloroquine diphosphate Primaquine Antimalarials Antiprotozoal Agents Antiparasitic Agents Anti-Infective Agents Antineoplastic Agents |
Antiviral Agents Schistosomicides Antiplatyhelmintic Agents Anthelmintics Amebicides Antirheumatic Agents Anti-Inflammatory Agents, Non-Steroidal Analgesics, Non-Narcotic Analgesics Sensory System Agents Peripheral Nervous System Agents Physiological Effects of Drugs Anti-Inflammatory Agents Filaricides Antinematodal Agents |