LIQUID-CHROMATOGRAPHIC ASSAY FOR DEXTROMORAMIDE IN HUMAN PLASMA

Dextromoramide is a narcotic analgesic drug which has been said to be clinically useful where rapid onset and short duration of action is re quired. The present communication describes a modification of previous high performance liquid chromatographic methods for determining plasm a dextromoramide concentrations. The method described is sensitive, ac curate and precise, with intra-assay CV's of 4.1%, 4.1% and 4.2% and b etween-assay CV's of 2.9%, 2.4% and 3.9% at concentrations of 10, 100 and 1000 mu g/L, respectively. It has a limit of quantitation of 5 mu g/L with a chromatographic run time of 8 min. Pharmacokinetic studies in 2 patients given 5mg of dextromoramide intravenously are presented as applications of this method. These studies showed a bi-exponential decay of dextromoramide in plasma over 24h with terminal half-lives of 3.7 and 23.5h which resulted from variability in plasma dextromoramid e clearance and distribution volumes.