madman
Super Moderator
Finasteride and dutasteride are 5-α-reductase inhibitors (5-ARIs) used to treat androgenetic alopecia (AGA). This review evaluates the efficacy of 5-ARIs for the treatment of men with AGA and the potential adverse effects on reproduction including sexual dysfunction, infertility, and teratogenicity. A broad literature review was conducted to search for publications on 5-ARI treatment in men with AGA. Hair counts, hair growth assessments, sexual adverse effects (erectile dysfunction, ejaculatory dysfunction, and decreased libido), changes in sperm parameters (decreased sperm count, semen volume, sperm motility), and teratogenic drug concentration levels in semen were the measured outcomes of studies included in this literature review. Both finasteride and dutasteride are effective at treating hair loss in male AGA, with studies finding dutasteride was more efficacious than finasteride. Many studies reported sexual adverse effects of 5-ARIs that are uncommon and resolve spontaneously, although there remains no consensus with respect to the presence, severity, and duration of sexual adverse effects. 5-ARIs may have a negative impact on spermatogenesis although the clinical significance of this is unclear and discontinuation of these medications results in improved sperm parameters for most patients. Teratogenicity after paternal exposure is unlikely due to the low concentration of 5-ARIs absorbed in semen. Further research is needed to evaluate the effects of 5-ARI use on reproduction.
Introduction
Male pattern hair loss, also called male androgenetic alopecia or androgenetic alopecia (AGA), is the most common cause of hair loss in men.1 AGA is a skin condition characterized by changes to hair cycle, follicular miniaturization, and inflammation that contribute to a pattern of progressive hair loss. AGA in men usually begins to manifest itself between adolescence and age 30 years, with a younger onset predicting a more severe form of the condition. By age 50 years, approximately 50% of men are affected to some extent by AGA.2 AGA affects as much as 80% of the male population.3 Hair loss from AGA has been correlated with decreased quality of life and psychological distress.4 Given its high prevalence and psychosocial morbidity, there is a demand for treatment options.
AGA is a genetic disorder with an excessive response to androgens. Finasteride and dutasteride are 5-α-reductase inhibitors (5-ARIs) used in the treatment of AGA by preventing the conversion of testosterone to dihydrotestosterone(DHT) because suppression of circulating levels of DHT is thought to improve hair growth in men with AGA. During normal hair growth, activation of the androgen receptor shortens the anagen (growth) phase. It has been proposed that excessive activation of the androgen receptor by DHT leads to progressively shorter anagen phases and follicular miniaturization.5 This results in shorter and thinner hair follicles that are unable to reach the surface of the scalp creating the appearance of hair loss seen in patients with AGA.5-ARIs are also used at higher doses to treat benign prostatic hyperplasia(BPH). There have been adverse sexual health effects reported with 5-ARIuse including erectile dysfunction, decreased libido, and ejaculation disorders. There is also a concern for teratogenicity and potential effects on spermatogenesis. This literature review provides an overview of published research on the efficacy of finasteride and dutasteride for the treatment of AGA in men and the potential for adverse effects on reproduction.
Treatment With 5-ARIs
5-ARIs are thought to improve hair growth in men with AGA by reducing the amount of circulating DHT and thus its potential impact on androgen receptors. There are two 5-ARIs used for the treatment of AGA: finasteride and dutasteride.
*oral finasteride
*oral dutasteride
*comparison of oral finasteride and dutasteride
*topical finasteride efficacy
*topical dutasteride efficacy
Sexual Dysfunction With 5-ARI Use
Although 5-ARIs are considered well-tolerated medications, adverse sexual effects have been reported including decrease or loss of libido, ejaculatory dysfunction, and erectile dysfunction.24 Randomized clinical trials have demonstrated increased incidences of these adverse sexual effects in men taking finasteride and dutasteride.25
*finasteride
*persistent symptoms
*dutasteride adverse events
*comparison of finasteride and dutasteride
*topical finasteride adverse events
*topical dutasteride adverse events
Infertility With Finasteride and Dutasteride Use
The importance of DHT in spermatogenesis remains unclear and the potential impact of 5-ARIs use on fertility is controversial.
*finasteride
*dutasteride
*Teratogenicity
*finasteride teratogenicity
*dutasteride teratogenicity
Conclusions
Both finasteride and dutasteride are effective at treating hair loss in male AGA, with studies finding dutasteride is more efficacious than finasteride. Overall,there remains no consensus with respect to the presence, severity, or duration of sexual adverse effects induced by 5-ARIs, although many studies suggest that sexual adverse effects are uncommon and resolve spontaneously. Furthermore, it has been suggested that the reports of sexual dysfunction may be a result of a nocebo effect, drug dosage, duration of treatment, or disease process. For patients concerned about systemic adverse effects of oral 5-ARIs, topical administration may be effective at treating AGA with less potential for sexual adverse effects. 5-ARIs may have a negative impact on spermatogenesis and discontinuation of these medications results in improved sperm parameters in most patients. Teratogenicity after paternal exposure is unlikely due to the low concentration of 5-ARIs absorbed in semen. Further research is needed to clarify the effects of 5-ARI use on reproduction.
It is important for physicians treating AGA to counsel patients about the efficacy of 5-ARIs and the potential adverse effects prior to starting treatment. It is reasonable to consider screening patients taking finasteride for sexual adverse effects, even when using a low dose. If patients experience adverse effects, discontinuation should be considered and patients should be monitored for recovery of sexual function. Finasteride and dutasteride should be used with caution in men who desire fertility and should be considered on the differential during infertility evaluations. Barrier contraception during intercourse is recommended for female partners who are pregnant or may become pregnant. Furthermore, topical application of finasteride and dutasteride may be considered as a treatment option if patients want to avoid systematic reproductive adverse effects.
Introduction
Male pattern hair loss, also called male androgenetic alopecia or androgenetic alopecia (AGA), is the most common cause of hair loss in men.1 AGA is a skin condition characterized by changes to hair cycle, follicular miniaturization, and inflammation that contribute to a pattern of progressive hair loss. AGA in men usually begins to manifest itself between adolescence and age 30 years, with a younger onset predicting a more severe form of the condition. By age 50 years, approximately 50% of men are affected to some extent by AGA.2 AGA affects as much as 80% of the male population.3 Hair loss from AGA has been correlated with decreased quality of life and psychological distress.4 Given its high prevalence and psychosocial morbidity, there is a demand for treatment options.
AGA is a genetic disorder with an excessive response to androgens. Finasteride and dutasteride are 5-α-reductase inhibitors (5-ARIs) used in the treatment of AGA by preventing the conversion of testosterone to dihydrotestosterone(DHT) because suppression of circulating levels of DHT is thought to improve hair growth in men with AGA. During normal hair growth, activation of the androgen receptor shortens the anagen (growth) phase. It has been proposed that excessive activation of the androgen receptor by DHT leads to progressively shorter anagen phases and follicular miniaturization.5 This results in shorter and thinner hair follicles that are unable to reach the surface of the scalp creating the appearance of hair loss seen in patients with AGA.5-ARIs are also used at higher doses to treat benign prostatic hyperplasia(BPH). There have been adverse sexual health effects reported with 5-ARIuse including erectile dysfunction, decreased libido, and ejaculation disorders. There is also a concern for teratogenicity and potential effects on spermatogenesis. This literature review provides an overview of published research on the efficacy of finasteride and dutasteride for the treatment of AGA in men and the potential for adverse effects on reproduction.
Treatment With 5-ARIs
5-ARIs are thought to improve hair growth in men with AGA by reducing the amount of circulating DHT and thus its potential impact on androgen receptors. There are two 5-ARIs used for the treatment of AGA: finasteride and dutasteride.
*oral finasteride
*oral dutasteride
*comparison of oral finasteride and dutasteride
*topical finasteride efficacy
*topical dutasteride efficacy
Sexual Dysfunction With 5-ARI Use
Although 5-ARIs are considered well-tolerated medications, adverse sexual effects have been reported including decrease or loss of libido, ejaculatory dysfunction, and erectile dysfunction.24 Randomized clinical trials have demonstrated increased incidences of these adverse sexual effects in men taking finasteride and dutasteride.25
*finasteride
*persistent symptoms
*dutasteride adverse events
*comparison of finasteride and dutasteride
*topical finasteride adverse events
*topical dutasteride adverse events
Infertility With Finasteride and Dutasteride Use
The importance of DHT in spermatogenesis remains unclear and the potential impact of 5-ARIs use on fertility is controversial.
*finasteride
*dutasteride
*Teratogenicity
*finasteride teratogenicity
*dutasteride teratogenicity
Conclusions
Both finasteride and dutasteride are effective at treating hair loss in male AGA, with studies finding dutasteride is more efficacious than finasteride. Overall,there remains no consensus with respect to the presence, severity, or duration of sexual adverse effects induced by 5-ARIs, although many studies suggest that sexual adverse effects are uncommon and resolve spontaneously. Furthermore, it has been suggested that the reports of sexual dysfunction may be a result of a nocebo effect, drug dosage, duration of treatment, or disease process. For patients concerned about systemic adverse effects of oral 5-ARIs, topical administration may be effective at treating AGA with less potential for sexual adverse effects. 5-ARIs may have a negative impact on spermatogenesis and discontinuation of these medications results in improved sperm parameters in most patients. Teratogenicity after paternal exposure is unlikely due to the low concentration of 5-ARIs absorbed in semen. Further research is needed to clarify the effects of 5-ARI use on reproduction.
It is important for physicians treating AGA to counsel patients about the efficacy of 5-ARIs and the potential adverse effects prior to starting treatment. It is reasonable to consider screening patients taking finasteride for sexual adverse effects, even when using a low dose. If patients experience adverse effects, discontinuation should be considered and patients should be monitored for recovery of sexual function. Finasteride and dutasteride should be used with caution in men who desire fertility and should be considered on the differential during infertility evaluations. Barrier contraception during intercourse is recommended for female partners who are pregnant or may become pregnant. Furthermore, topical application of finasteride and dutasteride may be considered as a treatment option if patients want to avoid systematic reproductive adverse effects.
