VENLAFAXINE - PHARMACOLOGY AND THERAPEUTIC POTENTIAL IN THE TREATMENTOF DEPRESSION

Venlafaxine is the first available antidepressant of the structurally novel SNRI (serotonin noradrenaline-reuptake inhibitor) class of drugs . It resembles the tricyclics in its ability to inhibit presynaptic re uptake of both serotonin and noradrenaline to a clinically significant degree. However, it does not cause appreciable effects at other recep tor sites, including cholinergic, adrenergic and histaminergic, which are responsible for most of the unwanted side effects and toxicity ass ociated with antidepressant treatment. It has the unusual ability to r educe beta-noradrenergic responsiveness after a single dose, which has led to the suggestion that it may have an earlier onset of therapeuti c effect than traditional antidepressants. Clinical trials provide evi dence that venlafaxine is of comparable efficacy to reference antidepr essants, but may have a faster onset of antidepressant effect when giv en in high dosage. (C) 1998 John Wiley & Sons, Ltd.