Action of propranolol in mania: comparison of effects of the d- and the l-stereoisomer.

The antimanic action of high doses of the beta-receptor blocking agent propranolol was investigated by the use of a double-blind placebo controlled ABA design. For comparison, the d-stereoisomer (which is practically devoid of beta-blocking activity) was used. 6 trials were performed with d-propranolol, 6 trials with the racemic mixture. From dose-effect relations one can conclude that the d-stereoisomer is about half as effective against manic syndromes as the racemic mixture. From this finding it can be concluded that the antimanic action of propranolol is at least partially due to a mechanism independent of its beta-blocking action.