[Studies on the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine].

The method for the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine by means of GC/NPD and GC/MSD is described. TFAA and MSTFA-MBTFA have been used in this procedure for TFA and TMS derivatization. The parent forms and the metabolites of the four drugs can be found by GC/NPD screening and GC/MSD confirmation. The method is reliable, fast and sensitive.

Kinetics of idaverine in healthy male subjects after single dose oral and intravenous administration.

The kinetics of idaverine was studied in an open, cross-over, partially randomized design after single oral (2 mg) and intravenous (1 and 2 mg doses to 12 healthy male subjects. In the first session, the volunteers were administered 1 mg idaverine by constant intravenous infusion during 45 min. The treatments in the second and third sessions were given according to a cross-over design, randomized in blocks of six for each session (2 mg either orally or by intravenous infusion during 45 min). The washout period between the sessions was at least 1 week. Plasma, urine and faeces were analysed for idaverine and its pharmacologically active metabolite N-desmethylidaverine by gas chromatography with nitrogen flame ionisation detection. After intravenous administration, the MRT was on average 2 hours and the mean CLS was about 900 ml.min-1. CLR is about twice the glomerular filtration rate, suggesting net tubular secretion of idaverine. The AUC and the cumulative urinary and faecal excretion values gave no indication of dose-disproportionality within the range of 1 and 2 mg administered intravenously. Maximum plasma levels of 1-3 ng.ml-1 were reached between 0.5 hours and 3 hours after oral dosing. The MRT was 4.4 hours. Systemic availability was about 29%. N-desmethylidaverine was barely detectable in plasma after all doses. Idaverine was well tolerated, only a small increase in heart rate was observed.