IT IS SELECTIVE SEROTONIN REUPTAKE INHIBITOR. THE ANTIDEPRESSANT, NTIOBSESSIVE-COMPULSIVE, AND ANTIBULIMIC ACTIONS OF FLUOXETINE ARE PRESUMED TO BE LINKED TO ITS INHIBITION OF CNS NEURONAL UPTAKE OF SEROTONIN. ANTAGONISM OF MUSCARINIC, HISTAMINERGIC, AND ALPHA1-ADRENERGIC RECEPTORS HAS BEEN HYPOTHESIZED TO BE ASSOCIATED WITH VARIOUS ANTICHOLINERGIC, SEDATIVE, AND CARDIOVASCULAR EFFECTS OF CLASSICAL TRICYCLIC ANTIDEPRESSANT DRUGS. FLUOXETINE BINDS TO THESE AND OTHER MEMBRANE RECEPTORS FROM BRAIN TISSUE MUCH LESS POTENTLY IN VITRO THAN DO THE TRICYCLIC DRUGS.