[Relative bioavailability and influence of a quinidine retard-formulation on blood-pressure and ECG in healthy volunteers (author's transl)].

In the present study on healthy volunteers plasma levels of (5-vinyl-2-quinuclidinyl)--(6-methoxy-4-quinolyl)-methanol (quinidine, Chinidinorm) and ECG were studied after administration of a single oral dose of 492 mg quinidine-base as quinidine-bisulfate in form of two slow-release formulations with different galenics. Both formulations show similar retard-characteristics. Serum concentration curve, area under the serum concentration curve, peak serum quinidine levels (1.44 mg/l for both formulations), apparent elimination rate constant (k2 = 0.0882 and 0.0805 h-1, respectively) and elimination half-life show no significant differences. Under the influence of quinidine there is a small but significant increase of the systolic blood pressure during peak serum quinidine levels. The ECG shows increased QT-duration, T-peak and R-peak. There are no significant differences between the two slow-release formulations.