Comparative cardiac effects of antimalarial drug halofantrine with or without concomitant administration of kolanut or fluconazole in healthy volunteers.

Background: There is rekindled interest in the cardiotoxicity of antimalarial medicines. Halofantrine is associated with QT interval prolongation. Fluconazole and kolanut alter the pharmacokinetics of halofantrine.

Effect of kolanut on the pharmacokinetics of the antimalarial drug halofantrine.

Objective: To study the effect of the concomitant consumption of kolanut, a caffeine-containing nut, on the pharmacokinetics of halofantrine.

Methods: A single dose of 500 mg halofantrine hydrochloride was orally administered either alone or concomitant with 12.5 g kolanut to 15 healthy male volunteers in a Latin-square randomized crossover design with a wash-out period of 6 weeks between treatments.

Analysis of the antimalarial drug halofantrine and its major metabolite N-desbutylhalofantrine in human plasma by high performance liquid chromatography.

The determination of halofantrine and its major metabolite N-desbutylhalofantrine in human plasma by reversed phase high-pressure liquid chromatography is described. The method involves protein precipitation of plasma samples by acetonitrile followed by basification with sodium hydroxide and subsequent liquid-liquid extraction using hexane-diethyl ether (1:1, v/v). The chromatographic separation was carried out on a C-18 column with a mobile phase consisting of methanol/0.

Kinetics of thermal decomposition of 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD).

The kinetics of thermal decomposition of 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD), an arenediazonium ion newly developed as a derivatizing reagent for drug analysis, are described. The arenediazonium ion, in an optimized concentrated sulfuric acid/orthophosphoric acid medium, was incubated for various time intervals at 30 degrees, 45 degrees, 55 degrees , 65 degrees , 75 degrees, and 85 degrees C. The amount of ion left after each time interval was quantified selectively by colorimetric assay at 490 nm, using mefenamic acid as a model diazo-coupling component.