Determination of dextromoramide in plasma and whole blood using high-performance liquid chromatography with ultraviolet absorbance detection.

Dextromoramide was determined in plasma and whole blood after solid-phase isolation by high-performance liquid chromatography using dextropropoxyphene as internal standard and ultraviolet detection at 215 nm. Owing to its good selectivity, sensitivity and reproducibility, the technique is available for forensic toxicology purposes as well as for clinical pharmacology. The concentrations of dextromoramide were determined in three cancer patients receiving intravenous treatment with one to three 5-mg daily doses. On the fourth day the plasma level was 13.85 +/- 3.27 ng ml-1 just before the first daily dose and 84.28 +/- 12.60 ng ml-1 30 min after dosing. The whole blood concentration, determined in one of the patients, was undetectable just before the dose and was 76 ng ml-1 30 min after dosing.