Venlafaxine sexual function

Bupropion appears to be relatively free of adverse effects on sexual function, in contrast to the SSRIS or venlafaxine (168). 

SSRIs and venlafaxine can cause of variety of sexual dysfunctions including delayed ejaculation, anorgasmia, and decreased libido ( Table 7-24). For two reasons, the adverse effect of these medications on sexual function was underestimated during the early clinical trials. First, such trials rely on spontaneous reporting by participants. Second, these adverse effects appear to take several weeks to develop. These adverse effects develop in approximately 30% to 40% of patients on adequate doses of SSRIs and venlafaxine. Although all manufacturers of these medications endeavor to suggest that their product is less likely to cause these effects, there is no compelling evidence to indicate that is true. Comparisons of rates across studies are not fair comparisons because they may differ based on how these problems were assessed. 

Antidepressant drugs can rarely cause priapism. The agent most often implicated has been trazodone, perhaps because of its ai-adrenoceptor antagonist properties. In general venlafaxine has an inhibitory effect on sexual function, but perhaps, like SSRIs, it can rarely cause priapism (23). 

There are many other ways in which SSRIs can interfere with sexual function, for example by causing loss of sexual interest and erectile difficulties. In an open, prospective study of 1000 Spanish patients taking a variety of antidepressants, there was an overall incidence of sexual dysfunction of 59% (15). The highest rates, 60-70%, were found with SSRIs (including flu-voxamine) and venlafaxine. The lowest rates were found with mirtazepine (24%), nefazodone (8%), and moclobemide (4%). Spontaneous resolution of this adverse effect was uncommon - 80% of subjects had no improvement in sexual function over 6 months of treatment. 

Kennedy SH, Rizvi S, Fulton K, Rasmussen J. A double-blind comparison of sexual functioning, antidepressant efficacy, and tolerability between agomelatine and venlafaxine XR. J Clin Psychopharmacol 2008 28(3) 329-33. 

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