Clinical Trial: Study on the Treatment of Vivax Malaria

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

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

Brief Summary: This is a randomised open label trial with follow up for 1 year. 660 adults and children above 6 months diagnosed with acute Plasmodium vivax will be randomised into 3 groups, either chloroquine, artesunate, or chloroquine/primaquine therapy. Participants will be screened on the day of inclusion then followed weekly for 8 visits and every 4 weeks until week 52. The primary objective of the study is to compare the efficacy of the WHO and Thai Ministry of Public Health recommended radical curative regimen of chloroquine and primaquine with the currently used monotherapy regimens of chloroquine and artesunate along the Thai-Burmese border.

Detailed Summary:

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
Sponsor: University of Oxford

Current Primary Outcome: The first recurrence of Plasmodium vivax malaria [ Time Frame: Day 28 ]

The first recurrence of Plasmodium vivax malaria within 28 days


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • 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


Original Secondary Outcome: Same as current

Information By: University of Oxford

Dates:
Date Received: February 23, 2010
Date Started: May 2010
Date Completion:
Last Updated: August 27, 2013
Last Verified: August 2013