Evaluation of Sexual Function With an International Index of Erectile Function in Subjects Taking Finasteride for Androgenetic Alopecia FREE

Because a systemic treatment for androgenetic alopecia (AGA) is now available, a careful balance between benefits and potential unfavorable consequencesis necessary. One of the aspects that has gained increasing attention in this respect is sexual function.

The main adverse effects related to finasteride therapy for AGA involve the sphere of sexual function (loss of libido, erectile dysfunction, and decreased ejaculate volume). In clinical trials for the evaluation of finasteride efficacy, sexual side effects have been reported in 4.4% of patients treated with theactive drug and in 2.2% of patients taking placebo,^1- 3 with 1.4% of patients discontinuing the studies because of sexual side effectsin the first year of treatment and 1.3% discontinuing in the extension studies. These adverse effects are less apparent in the clinical setting, where sexualside effects occur in fewer than 0.5% of subjects who take 1 mg of finasteride.⁴

The abridged 5-item version of the International Index of Erectile Function(IIEF-5) is a cross-culturally and psychometrically valid measure of malesexual function that has been used to measure the efficacy of oral sildenafil citrate and oral phentolamine mesylate in the treatment of erectile dysfunction.^5- 7 The IIEF-5, which isa brief, reliable self-administered questionnaire consisting of 15 questions, has been linguistically validated in 31 languages, including Italian. It evaluates5 domains: erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall sexual satisfaction.^5- 7 Theerectile function domain of the IIEF-5 is considered a valid diagnostic tool for distinguishing between men with and without erectile dysfunction. An erectilefunction score of less than 25 is indicative of erectile dysfunction. The IIEF-5 demonstrates adequate sensitivity and specificity for detecting treatment-relatedchanges in patients with erectile dysfunction.⁵

In a preliminary study, we showed that the sexual and erectile functions of subjects taking finasteride do not significantly differ from those of age-matchedcontrols.⁴ The aim of our current study was to evaluate variations in sexual and erectile functions in subjects taking1 mg of finasteride for AGA by administering the IIEF-5 before and duringtreatment.

In a multicenter study carried out in Italy, the sexual function of a group of 186 patients with AGA was evaluated before and 4 to 6 months afterthe initiation of finasteride therapy (1 mg). All patients (age range, 19-43years; mean age, 28.3 years), who were followed up as outpatients in 7 dermatologydepartments in Italy (Bologna, Rome, Genoa, Cagliari, Milan, Florence, andBari), agreed to take the self-administered IIEF-5.

Possible changes in score after 4 to 6 months of treatment vs baseline values were considered within the 5 domains of the questionnaire (partialscore) and within each question. Statistical analysis was performed by means of the Wilcoxon test for paired nonparametric data. Table 1 shows the patients' score on each of the 5 domains of thequestionnaire before (at baseline) and after 4 to 6 months of treatment. No changes were statistically significant.

The development of AGA clearly involves a combination of androgens, genetics, and aging. Follicle miniaturization occurs mainly as a result ofdihydrotestosterone (DHT). Oral finasteride therapy (1 mg) lowers serum, prostate, and scalp DHT levels and is effective in treating AGA because it inhibitsthe conversion of testosterone to DHT. Finasteride is a well-tolerated drug, and the only reported adverse effects involve sexual function.

Androgens are known to play an important role in erectile function, and androgen receptors have been identified in cavernosal tissue of rats,although the involvement and precise role of these steroids in humans remains to be established.^8- 9 Hypothetically,finasteride could cause loss of libido, erectile dysfunction, and decreasedejaculate volume by a reduction in serum and prostate levels of DHT.^10- 11 Studies have shown that the drugdoes not affect spermatogenesis or semen production in young men.¹²

Finasteride-induced sexual dysfunction is nevertheless a benign condition that completely resolves after therapy is discontinued. Sexual dysfunctionhas also resolved in most men who reported the condition but who continued to take finasteride anyway.³ The drug doesnot produce significant changes in serum levels of gonadotropins (leutinizing hormone and follicle-stimulating hormone) or in estrogen-testosterone ratios,although testosterone and estrogen levels slightly increase (approximately 15%) during treatment.^3,11

In clinical experience, sexual side effects occur in fewer than 0.5% of subjects who are on a 1-mg regimen of finasteride.⁴ Trialson the long-term use of 1 mg of finasteride (>4000 men studied in clinical trials for ≤6 years) show that the incidence of adverse effects does notincrease with continuation of treatment.³ However, men with AGA are often severely psychologically affected by their hair lossand therefore can be more susceptible to the psychological impact of possible sexual side effects. Our study using an objective method, the IIEF-5 questionnaire,showed that erectile function of all patients remained stable after 4 to 6months of treatment with finasteride (1 mg).

Our results support the clinical impression that sexual side effectsare actually less common than is reported in clinical trials. This discrepancymay be attributable to the fact that subjects who enrolled in the clinicaltrials were informed about possible changes in their sexual function and werespecifically asked about such changes at every visit, resulting in a higher percentage of reported adverse events than would normally occur. Physicianswho prescribe the drug on a daily basis see sexual effects much more rarely, even if they inform their patients about the possible occurrence of theserare side effects. We did not evaluate changes in the ejaculate volume in this study because this subject is not assessed by the questionnaire, althougha decrease in ejaculate volume is not rare in our experience.

We believe that the IIEF-5 could be routinely administered to subjects who wish to begin taking finasteride but are particularly worried about sexualside effects. In our experience, the questionnaire is well accepted by patients, who are often anxious about the possible occurrence of sexual side effectsand who are eager to be carefully followed up during treatment.

Correspondence: Antonella Tosti, MD, Department of Dermatology, Universityof Bologna, Via Massarenti 1, 40138 Bologna, Italy (tosti@med.unibo.it).

Accepted for publication October 8, 2003.