SSRIs, bupropion, and sexual function - selective serotonin reuptake inhibitors - JFP Journal Club

Journal of Family Practice, August, 1997 by Neva Edens, Warren P. Newton

Clinical question What effects do selective serotonin reuptake inhibitors (SSRIs) and bupropion have on sexual function?

Background The inhibitory effects of SSRIs on sexual function have been extensively described in previous studies, with frequencies ranging from 1% to 75%. Bupropion, in contrast, has been noted to have few adverse effects on sexual function and may promote sexual function. This study assessed both adverse and beneficial effects on specific aspects of sexual functioning in patients taking SSRIS and bupropion.

Population studied The study population consisted of 107 adult patients in a university outpatient psychiatric clinic taking bupropion (n=22), fluoxetine (n=37), paroxetine (n=20), or sertraline (n=27) for at least 1 week. Of these, 88 had major depression. Participants reported no symptomatic medical problems or sexual dysfunction preceding the onset of psychiatric symptoms. In addition, they were taking no other psychiatric medications except for alprazolam (n=4) or clonazepam (n=5) and no medications known to affect sexual function. Similarities between study patients and those seen by family physicians are difficult to assess. Depression is common in primary care, but the severity of the depression, reasons for referral, or characteristics such as race, marital status, and socioeconomic status were not described in this population.

Study design and validity This is a case series in which patients attending an outpatient clinic were given an anonymous questionnaire. Patients were blinded to the study hypotheses. The questionnaire had not been previously validated; the response rate was not specified and may have been as low as 33%. Appropriate statistical tests were used to assess differences among the drugs as well as the impact of possible confounding factors. Correction for multiple comparisons was made.

Overall, the internal validity of the study was poor. The low response rate suggests the possibility of selection bias, including only those subjects who cared to answer the survey. Participants were asked to compare current sexual function with their baseline function before the onset of psychiatric symptoms. The accuracy of recall of such taboo and intensely subjective information is suspect. Medication was not randomly allocated, increasing the opportunity for confounding, since many factors known to be important for sexual behavior (marital status, sexual orientation, number of partners, sexual techniques, and socioeconomic status) were not measured.

Outcomes measured Subjects were asked to compare their current level of libido, level of arousal, duration of time from arousal to orgasm, intensity of orgasm, and duration of orgasm with their status before onset of psychiatric symptoms. No questions were asked about overall sexual satisfaction or its relative significance compared with other aspects of lifestyle. Therapeutic response, other adverse effects, costs, and impact on partners were not addressed.

Results Of the patients taking SSRIs, 73% reported worsening of one or more aspects of sexual functioning, with highly significant results for libido, arousal, time from arousal to orgasm, intensity of orgasm, and duration of orgasm (all comparisons with bupropion, P [is less than] .0001). There were no significant differences among the different SSRIs. The number needed to treat (NNT) of patients taking an SSRI for worsening sexual function was 1.3. By contrast, only 14% of the patients taking bupropion reported a decline in any specific aspect of sexual function, and 77% showed improvement in sexual functioning. The NNT for patients taking bupropion to improve sexual functioning was 1.3. Sex, age, psychiatric diagnosis, drug dosage, and duration did not confound findings, although the small numbers of subjects in each of the subgroups may have weakened the power of this assessment.

Recommendations for clinical practice Patients taking bupropion reported less sexual dysfunction than those taking SSRIs. The weak design of the current study limits inference, but the most solid finding is the high prevalence of sexual dysfunction in patients taking SSRIs, confirming previous work. Given the reluctance of both patients and physicians to volunteer discussion of sexual function, these results underscore the importance of addressing sexual function explicitly. The most provocative result, ie, that bupropion may improve sexual functioning, needs confirmation from prospective randomized controlled trials.