VENLAFAXINE - MEASURING THE ONSET OF ANTIDEPRESSANT ACTION

Venlafaxine, a new antidepressant, inhibits reuptake of norepinephrine and serotonin without appreciable effects on histaminergic, alpha-adr energic, or cholinergic systems. Pharmacologically the drug is unique: the half-life is short and it exerts both rapid and prolonged beta-ad renergic desensitization after single doses in a rodent model. Venlafa xine has been thought to possess a rapid onset of clinical antidepress ant action. Accordingly, two clinical studies in which moderate amount s of venlafaxine were given aggressively were reviewed to examine aspe cts of the drug's onset of action. Three statistical methodologies wer e employed-traditional analysis of depression scale scores, pattern an alysis based on timing and persistence of response, and survival analy sis of sustained response. All three methods showed venlafaxine to hav e significant effects early in the course of therapy. In addition, ven lafaxine is the first drug to meet criteria for early onset using the pattern analysis methodology. Depressed patients aggressively treated with venlafaxine show significant benefit on or before Day 7 of treatm ent using traditional methods of analysis as well as survival analysis of sustained response.