Possible role of bulbocavernosus reflex latency in predicting sexual adverse effects of antidepressant medication

It is a well-known fact that psychotropic medication often results genitourinary and sexual adverse effects '. Accurate estimation of medication induced sexual dysfunction is difficult to obtain because many patients fail to report them and clinicians neglect to inquire about them. Sexual dysfunction may be idiosyncratic or associated with medical or psychiatric illness as well, making assessment of medication related dysfunction difficult. Authors used the technique of bulbocavernosus reflex latency measurement as a routine procedure in checking the functional innervation of the genital area. Coaxial needle electrodes are inserted into the bulbocavernosus muscle. Stimulation is on the dorsal side of the penile shaft and can be done using ring electrodes of a surface stimulator. The intensity required in this case is usually 5 to 20 mA and the duration is 0.1 ms. Values are measured to the onset of the negative peak. We consider the values 34 + 3 ms (mean + 1 SD) as fully normal, 38-42 ms as dubious. Values > 42 ms are pathological. We found that 69 % of the men presenting > 42 ms values complain about disturbed or missing erection, while only 17 % of the dubious group (DG) and 13 % of the males with normal values (NVG) do the same. When receiving a psychotropic medication the overall rate of erectile dysfunction increases to 16 % in NVG, while to 77 % in DG. While initial and after-drug-induction percentages do not differ too much in NVG, they show a great difference in DG. On the basis of these preliminary findings we suggest that bulbocavernosus reflex latency should be screened before initiating a psychotropic medication and, if there is a choice, drugs with less sexual side effects should be given to patients with dubious latency values, predicting a greater likelihood of the development of a drug-induced erectile dysfunction.