ISSN:
0899-0042
Keywords:
(R)-
;
(S)-
;
(R, S)-amlodipine
;
pharmacokinetics
;
oral dosage
;
human study
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Plasma concentrations of (R)- and (S)-amlodipine were measured after single oral administrations to 18 healthy volunteers of 20 mg amlodipine racemate. The contribution of the pharmacologically active (S)-enantiomer to the concentrations of total amlodipine (sum of enantiomers) was significantly higher than that of the inactive (R)-enantiomer, with mean values of 47% R to 53% S for the Cmax and 41% R to 59% S for the AUC (range between 24% R:76% S and 50% R:50% S). The oral clearance of the active (S)-form was subject to much less intersubject variation (25% CV) than that of the inactive (R)-form (52% CV). (R)-Amlodipine was more rapidly eliminated from plasma than (S)-amlodipine, with mean terminal half-lives of 34.9 h (R) and 49.6 h (S). The terminal half-lives of total amlodipine (mean 44.2 h) were strongly correlated with - and thus highly predictive for - the half-lives of the (S)-enantiomer. It is proposed that the observed enantioselectivity of oral amlodipine is due to differences in the systemic blood clearance of the enantiomers. © 1994 Wiley-Liss, Inc.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chir.530060704
