Pharmacokinetic and pharmacodynamic properties of alinidine in man

The elimination kinetics of alinidine and the changes in heart rate and blood pressure were determined in five health subjects following intravenous and oral administration of single doses of 40 mg alinidine. The plasma concentration after the intravenous injection declined at least biexponentially with time, with mean half-lives of 0.6 +/- 0.15 h and 3.9 +/- 0.28 h for the distribution and the elimination phase, respectively. The mean total clearance amounted to 40.3 +/- 8.9 L/h and the renal clearance to 33.6 +/- 12.3 L/h. The bioavailability following oral administration was nearly complete (0.92 +/- 0.06). Alinidine produced a modest bradycardia effect in healthy subjects. The maximal decrease in the heart rate was 19.2 +/- 7.7% (p less than 0.05) and 14.2 +/- 8.1% (p less than 0.05) following intravenous and oral administration, respectively. Time intervals in surface electrocardiogram (duration of the P- wave, PG time, QRS duration, and QTc) were not significantly altered by alinidine after both routes of administration. There was also a slight but consistent decrease in the systolic blood pressure (3-8%) after both routes of administration, whereas the diastolic blood pressure remained unchanged.