MedPath

Safety and Tolerability of Low Dose Primaquine

Phase 4
Completed
Conditions
Malaria, Falciparum
G6PD Deficiency
Interventions
Registration Number
NCT02434952
Lead Sponsor
Malaria Consortium
Brief Summary

In Cambodia, falciparum is becoming more difficult to treat because drugs are becoming less effective. The investigators can help to try to prevent the spread of this resistant malaria by adding a drug that will make it more difficult for the mosquito to drink up the malaria in people's blood. If the mosquito cannot drink up the malaria, then the malaria cannot develop in the mosquito so it will not be able to inject malaria back into people when it bites. The drug the investigators will use is called primaquine.

Primaquine commonly causes the red cells in the blood to break apart if they are weak. Red cells need enzymes to work properly and weak red cells have low amounts of an enzyme called glucose 6 phosphate dehydrogenase (G6PD). The investigators want to know if treating malaria with primaquine will be safe for the red cells. To do this study, the investigators need to know if a subject has low G6PD or not.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
109
Inclusion Criteria
  • Age ≥ 1 year
  • Presentation with a confirmed fever (≥ 38⁰C axilla or ≥ 37.5⁰C aural) or history of fever in previous 48 hours +/- other clinical features of uncomplicated malaria
  • Plasmodium falciparum monoinfection ≥ 1 asexual form / 500 white blood cells
  • Informed consent (written/verbal) provided by patient or relative/legal guardian
  • Signed Assent form for children aged 12 to < 18 years
Exclusion Criteria
  • Clinical signs of severe malaria or danger signs
  • Pregnant or breast feeding
  • Unable or unwilling to take a pregnancy test (for women of child-bearing age)
  • Women intending to become pregnant in the next 3 months
  • Allergic to primaquine or DHA PP
  • Patients taking drugs known to cause acute intravascular haemolytic anaemia (AIHA) in G6PD deficiency e.g. dapsone, nalidixic acid
  • Patients on treatment for a significant illness e.g. HIV, tuberculosis (TB) treatment, steroids
  • On drugs that could interfere with anti-malarial pharmacokinetics like antiretrovirals, cimetidine, ketoconazole, antiepileptic drugs, rifampicin

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
DHA PP plus primaquine, G6PD deficiencyDihydroartemisinin piperaquine (DHA PP)Standard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP. Target dose of 0.25mg/kg primaquine given orally with first dose only of DHA PP, dosing by weight for children \<18 years and standard 15mg primaquine dose for all adults ≥18 years. Small children (\<25kg) will receive a primaquine suspension, adults receive 7.5mg or 15mg primaquine tablets.
DHA PP alone, G6PD deficiencyDihydroartemisinin piperaquine (DHA PP)Standard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP.
DHA PP plus primaquine, G6PD normalDihydroartemisinin piperaquine (DHA PP)Standard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP. Target dose of 0.25mg/kg primaquine given orally with first dose only of DHA PP, dosing by weight for children \<18 years and standard 15mg primaquine dose for all adults ≥18 years. Small children (\<25kg) will receive a primaquine suspension, adults receive 7.5mg or 15mg primaquine tablets.
DHA PP alone, G6PD normalDihydroartemisinin piperaquine (DHA PP)Standard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP.
DHA PP plus primaquine, G6PD normalPrimaquineStandard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP. Target dose of 0.25mg/kg primaquine given orally with first dose only of DHA PP, dosing by weight for children \<18 years and standard 15mg primaquine dose for all adults ≥18 years. Small children (\<25kg) will receive a primaquine suspension, adults receive 7.5mg or 15mg primaquine tablets.
DHA PP plus primaquine, G6PD deficiencyPrimaquineStandard Dihydroartemisinin piperaquine (DHA PP) dosing according to national guidelines, oral administration of one dose per day for three consecutive days. Target dosing is 2-4 mg/kg for DHA and 20 mg/kg for PP. Children (\<30kg) will receive tablets of 20mg DHA and 160mg PP, while adults will receive tablets of 40mg DHA and 320mg PP. Target dose of 0.25mg/kg primaquine given orally with first dose only of DHA PP, dosing by weight for children \<18 years and standard 15mg primaquine dose for all adults ≥18 years. Small children (\<25kg) will receive a primaquine suspension, adults receive 7.5mg or 15mg primaquine tablets.
Primary Outcome Measures
NameTimeMethod
Haemoglobin concentrationDay 7

Compare haemoglobin concentrations in g/dL between the G6PD deficient arm given DHA PP plus primaquine, and the G6PD normal arm receiving the same regimen

Secondary Outcome Measures
NameTimeMethod
Proportion patients with ≥25% change in haemoglobin as a marker of intravascular haemolysisChange from Day 0 to Day 7

Comparing across all 4 arms: proportion of all patients with fractional change in haemoglobin ≥25% from day 0 to day 7

Plasma haemoglobin concentration as a marker of intravascular haemolysisDay 7

Comparing across all 4 arms: plasma haemoglobin concentration at day 7

Urine colour change as a marker of intravascular haemolysisChange from Day 0 to Day 7

Change in urine colour grade from day 0 to day 7 (Hillmen, Hall et al. 2004)

Fractional change in haemoglobin as a marker of intravascular haemolysisChange from Day 0 to Day 7

Comparing across all 4 arms: fractional change in haemoglobin on day 7 vs. day 0

Primaquine volume of distributionDay 0-7

Primaquine apparent volume of distribution (Vd), modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Clearance rate of piperaquineDay 0-28

Piperaquine elimination clearance rate, modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Piperaquine volume of distributionDay 0-28

Piperaquine apparent volume of distribution (Vd), modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Peak plasma concentration (Cmax) of piperaquineDay 0-28

Cmax taken directly from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Determine G6PD enzyme activityDay 0

Quantitative G6PD testing among all participants using the G6PD enzyme assay from Trinity Biologicals, USA, yielding G6PD enzyme results in U/g Hb.

Assess usefulness of field adapted WHO haemoglobin colour card vs. HemocueDay 0

Comparison of quantitative (HemoCue, g/dL HB) and qualitative (WHO haemolglobin colour card) estimates of haemoglobin concentration

Assess usefulness of rapid test for G6PDd in predicting acute intravascular haemolysisDay 0

Comparison of rapid G6PD test (AccessBio, USA) qualitative result against quantitative G6PD assay to determine predictive value for clinically significant haemolysis

Clearance rate of primaquineDay 0-7

Primaquine elimination clearance rate, modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Half life of primaquineDay 0-7

Primaquine terminal elimination half life, modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Half life of piperaquineDay 0-28

Piperaquine terminal elimination half life, modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Area under the plasma concentration versus time curve - piperaquineDay 0-28

Modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Peak plasma concentration (Cmax) of primaquineDay 0-7

Cmax taken directly from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Time to primquine peak plasma concentration (Tmax)Day 0-7

Tmax taken directly from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Time to piperaquine peak plasma concentration (Tmax)Day 0-28

Tmax taken directly from population pharmacokinetic data from all patients receiving at least one dose of DHA PP +/- PQ

Area under the plasma concentration versus time curve - primaquineDay 0-7

Modelled from population pharmacokinetic data from all patients receiving at least one dose of DHA PP + PQ

Trial Locations

Locations (1)

Ratanakiri Provincial Hospital

🇰🇭

Ratanakiri, Cambodia

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