RT Journal
A1 Zema M
T1 EQuivalence of generic and brand-name drugs for cardiovascular disease
JF JAMA
JO JAMA
YR 2009
FD April 22
VO 301
IS 16
SP 1654
OP 1656
DO 10.1001/jama.2009.521
UL http://dx.doi.org/10.1001/jama.2009.521
AB 
Phenylalkylamines, such as the verapamil derivatives, are marketed as a racemic mixture of enantiomers. The 2 enantiomers have been shown to have different pharmacodynamic activities. S-verapamil has demonstrated 20 times the potency on a weight basis compared with R-verapamil with regard to negative dromotropic effects on the cardiac conduction system.2 Most of the vasodilatory effects of this agent have been attributable to the R-enantiomer.2