GENDER-RELATED PHARMACOKINETICS OF DILTIAZEM IN HEALTHY-SUBJECTS

The aim of this study was to investigate the gender-related pharmacoki netic differences after a single oral dose of diltiazem (120 mg) in 12 healthy subjects (6 males and 6 females). Kinetic parameters were cal culated from serum concentrations obtained by means of a specific HPLC method. The total area under the concentration-time curve (AUC(0-infi nity)) was 917.03 +/- 342.13 ng.h(-1)/ml for females and 1,192.97 +/- 329.93 ng.h(-1)/ml for males. Peak serum levels (C-max) were 181.29 +/ - 48.03 ng/ml and 194.29 +/- 93.81 for females and males, respectively . The time to reach maximum concentration (T-max) was 2.2 +/- 0.8 h fo r both. The biological elimination t(1/2) was 4.58 +/- 2.08 h and 5.59 +/- 2.44 h, showing an elimination rate (k(el)) of 0.174 +/- 0.062 h( -1) and 0.149 +/- 0.075 h(-1), and a mean residence time (MRT) of 8.56 +/- 1.94 h and 8.88 +/- 2.78 h for females and males, respectively. M ale subjects showed higher values than females, but no significant dif ference was observed when comparing pharmacokinetic parameters by gend er. Diltiazem was well tolerated by all subjects.