INVESTIGATION OF A POSSIBLE PHARMACOKINETIC INTERACTION BETWEEN NISOLDIPINE AND QUINIDINE IN HEALTHY-VOLUNTEERS

Twenty healthy male volunteers completed an open, partially randomised , crossover study to assess a possible pharmacokinetic interaction bet ween nisoldipine and quinidine. Volunteers received either 1 nisoldipi ne coat-core 20mg tablet once daily, or 2 quinidine gluconate 324mg ta blets twice daily, according to a randomised 2-period crossover design . Between the 2 treatment periods there was a washout phase of 7 days. After a further washout phase of 7 days, all volunteers received niso ldipine coat-core 20mg (1 tablet) and quinidine gluconate 648mg (2 tab lets) concomitantly, as well as a second quinidine gluconate 648mg (2 tablets) dose 12 hours Inter. The results of this study indicate that the concomitant administration of nisoldipine and quinidine has no eff ect on the bioavailability of quinidine. However, it cannot be ruled o ut that the concomitant administration of these 2 drugs has an attenua ting effect on the bioavailability of nisoldipine, although the clinic al significance of a possible attenuation may be small in view of the very high intrasubject variation of this parameter. Concomitant admini stration of nisoldipine and quinidine was well tolerated.