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Safety and Preliminary Efficacy of L-arginine in Severe Falciparum Malaria

Phase 2
Suspended
Conditions
Severe Falciparum Malaria
Interventions
Other: Normal saline
Registration Number
NCT00616304
Lead Sponsor
Menzies School of Health Research
Brief Summary

Background: Mortality from severe malaria remains \~15% despite the use of the most rapidly parasiticidal antimalarial therapy, artesunate. Adjunctive treatments may improve outcome. Our overall goal is to determine if adjunctive treatment with L-arginine is safe and improves outcomes in severe malaria. In studies to date, we have shown that L-arginine is safe in moderately severe malaria, increases nitric oxide production and improves endothelial function. We now propose to extend these studies to patients with severe malaria.

Aims: To determine the safety, preliminary efficacy, pharmacokinetics and pharmacodynamics of L-arginine infusion in severe malaria.

Hypothesis: L-arginine will improve endothelial function, lactate clearance time and tissue oxygen delivery compared to saline with no clinically significant adverse effects.

Methods: Based on previous pharmacokinetic modeling and simulations, we propose a phase 2A randomised controlled trial of L-arginine vs saline in severe malaria, each given over 8 hours. If safety is demonstrated this will be followed by a phase 2B open-label study of 24-hour infusion of L-arginine in severe malaria with safety and preliminary efficacy compared with the 8 hour infusions given in phase 2A.

The primary outcomes will be the improvement in endothelial function and lactate clearance in patients given L-arginine infusion compared with those who received saline. Among the secondary outcomes will be safety and the effect of L-arginine vs saline on tissue oxygen delivery (NIRS).

Data from both phase 2A and 2B will be used to generate a pharmacokinetic/ pharmacodynamic model.

Detailed Description

See brief summary

Recruitment & Eligibility

Status
SUSPENDED
Sex
All
Target Recruitment
8
Inclusion Criteria
  1. age 18-60 years
  2. informed consent obtained
  3. time of commencement of artesunate ≤18 hrs before infusion of L-arginine
  4. any level of P. falciparum parasitemia, and one or more of the following criteria: i. acute renal failure (creatinine >265umol/L) ii. hyperbilirubinemia (total bilirubin >50 umol/L) with either renal impairment (creatinine >130umol/L) or parasitemia of >100,000 parasites/uL iii. blackwater fever iv. hyperparasitemia (>10% parasitised red cells) v. cerebral malaria (Glasgow coma score <11) vi. Hypoglycemia vii. Respiratory distress (RR >32)
Exclusion Criteria
  1. pregnancy or lactation
  2. diabetes
  3. serious pre-existing disease (cardiac, hepatic, kidney)
  4. systolic blood pressure <90 mmHg after fluid resuscitation
  5. initial iSTAT test showing any of the following values: i. K+ > 5.5 meq/L ii. Cl- > 110 meq/L iii. HCO3- < 15 meq/L
  6. known allergy to L-arginine
  7. evidence of concurrent bacterial infection
  8. concurrent therapy with any of the following medications: iv. spironolactone, v. oral nitrates, vi. phosphodiesterase inhibitor (eg sildenafil [Viagra]) vii. alpha-blocking antihypertensive agents (eg prazosin) viii. L-arginine

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
SNormal salineNormal saline infusion
AL-arginine hydrochlorideL-arginine infusion
Primary Outcome Measures
NameTimeMethod
Improvement in endothelial function and lactate clearance.Endothelial function: end of 8 hour infusion. Lactate clearance: area under the curve until lactate returns to the upper limit of normal
Secondary Outcome Measures
NameTimeMethod
Tissue oxygen consumption and delivery (NIRS)one and eight hours
improvement in RHPAT among those with baseline dysfunction (RHPAT<1.67)8 hours
parasite clearance timeparasite clearance time
Paired change in endothelial functionpaired comparison of post-vs pre-infusion values, overall, and in each arginine infusion regimen
Fever clearance timeFever clearance time
Safety: Clinical and biochemical measures.During and after infusion. In those receiving L-arginine, biochemical and hemodynamic measures at the completion of infusion will also be compared with measures at the start of infusion.
Change in endothelial function in each arginine infusion regimen vs saline placebo combined1 hour response and end of infusion response
Lactate clearance for each infusion regimenTime for lactate to return to upper limit of normal
Lactate:pyruvate ratioarea under curve/time to normal
Change in L-arginine concentrationat 1 and 8 hours
Improvement in microvascular obstruction (OPS)at 1 and 8 hours
change in exhaled NOone and eight hours
improvement in endothelial activation (decrease in angiopoietin-2 concentrations)area under curve

Trial Locations

Locations (1)

Mitra Masyarakat Hospital

🇮🇩

Timika, Papua, Indonesia

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