ISSN:
1432-1912
Keywords:
(R)-Propranolol
;
(S)-Propranolol
;
Betaadrenoceptor antagonists
;
Stereoselectivity
;
Iodocyanopindolol
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In a randomized, double-blind, placebo-controlled, cross-over study 24 healthy volunteers were examined before and 2 h after oral administration of 80 mg (R,S)-, 40 mg (R)- and 40 mg (S)-propranolol · HCI; 8 of them received placebo in an additional run. During exercise on a bicycle ergometer and a rest period the rate pressure product was decreased by 80 mg (R,S)-propranolol · HCl (−32.8%p 〈 0.0001) and 40 mg (S)-propranolol · HCl (−32.3%;p 〈 0.0001), whera 40 mg (R)-propranolol · HCl as well as placebo showed no effect. corresponding binding inhibition experiments using (−)-(125I)iodocyanopindolol in a sarcolemma-enriched cardiac membrane preparation yielded a eudismic ratio of 179 for (S)- over (R)-propranolol. 2 h after oral application, stereospecific HPLC analysis revealed different individual concentrations in plasma of (R)-(22.3 ± 21.7 ng/ml) and (S)-propranolol (30.4 ± 26.9 ng/ml) when 80 mg of (R,S)-propranolol · Hcl was administered. The plasma levels were similar when 40 mg of the pure enantiomer of (R)- (22.7 ± 20.3 ng/ml) or (S)-propranolol · HCl (28.7 ± 22.5 ng/ml) was applied. (R)- and (S)-propranolol are two substances with different pharmacodynamic and pharmacokinetic properties. As there are methods available to produce the optically pure enantiomers, they should be used rather than the racemic mixture.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00736064
Permalink
