Endocr Rev, Vol. 34 (03_MeetingAbstracts): SUN-528
Copyright © 2013 by The Endocrine Society
Sildenafil Increases Serum Testosterone Levels by a Direct Action on the Testes
Matthew Johnathan Spitzer, MD1, Shalender Bhasin, MD1, Thomas G Travison, PhD1, Maithili Davda, MPH1, Helene Stroh, BA1 and Shehzad Sultan Basaria, MD MBBS11 Boston University Medical Center, Boston,MA
Phosphodiesterase-5-inhibitors, such as sildenafil, increase intracavernosal cyclic guanosine monophosphate levels, which results in corporal vasodilatation and induces penile erection. Administration of sildenafil to male rats has been shown to increase serum testosterone levels by directly stimulating testicular Leydig cells. However, the effect of sildenafil on the hypothalamic-pituitary-gonadal axis in humans has not been evaluated in the setting of a large clinical trial. The Testosterone and Erectile Dysfunction trial (ClinicalTrials.gov # NCT00512707 ) administered an optimized dose of sildenafil in an initial run-in period to 140 men, age 40-70 years with erectile dysfunction and low testosterone levels (< 330ng/dL) and then randomized them to either transdermal testosterone or placebo gel. Serum testosterone, dihydrotestosterone and estrogens were measured using LC-MS/MS.
Administration of an optimized dose of sildenafil was associated with mean increases of 103ng/dL (P < 0.001) and 60.1pg/mL (P < 0.001) in total and free testosterone levels, respectively. This was accompanied by parallel increases in serum dihydrotestosterone (48.8pg/mL; P < 0.001), estradiol (3.7pg/mL; P < 0.001), and estrone (2.9pg/mL; P = 0.012) levels, and significant suppression of luteinizing hormone (change -1.3units/L; P = 0.003) levels, suggesting a direct effect at the testicular level. FSH and inhibin B levels remained unchanged.
Conclusion: Sildenafil administration was associated with increased testosterone levels likely due to a direct effect on the testis.
Nothing to Disclose: MJS, SB, TGT, MD, HS, SSB
Copyright © 2013 by The Endocrine Society
Sildenafil Increases Serum Testosterone Levels by a Direct Action on the Testes
Matthew Johnathan Spitzer, MD1, Shalender Bhasin, MD1, Thomas G Travison, PhD1, Maithili Davda, MPH1, Helene Stroh, BA1 and Shehzad Sultan Basaria, MD MBBS11 Boston University Medical Center, Boston,MA
Phosphodiesterase-5-inhibitors, such as sildenafil, increase intracavernosal cyclic guanosine monophosphate levels, which results in corporal vasodilatation and induces penile erection. Administration of sildenafil to male rats has been shown to increase serum testosterone levels by directly stimulating testicular Leydig cells. However, the effect of sildenafil on the hypothalamic-pituitary-gonadal axis in humans has not been evaluated in the setting of a large clinical trial. The Testosterone and Erectile Dysfunction trial (ClinicalTrials.gov # NCT00512707 ) administered an optimized dose of sildenafil in an initial run-in period to 140 men, age 40-70 years with erectile dysfunction and low testosterone levels (< 330ng/dL) and then randomized them to either transdermal testosterone or placebo gel. Serum testosterone, dihydrotestosterone and estrogens were measured using LC-MS/MS.
Administration of an optimized dose of sildenafil was associated with mean increases of 103ng/dL (P < 0.001) and 60.1pg/mL (P < 0.001) in total and free testosterone levels, respectively. This was accompanied by parallel increases in serum dihydrotestosterone (48.8pg/mL; P < 0.001), estradiol (3.7pg/mL; P < 0.001), and estrone (2.9pg/mL; P = 0.012) levels, and significant suppression of luteinizing hormone (change -1.3units/L; P = 0.003) levels, suggesting a direct effect at the testicular level. FSH and inhibin B levels remained unchanged.
Conclusion: Sildenafil administration was associated with increased testosterone levels likely due to a direct effect on the testis.
Nothing to Disclose: MJS, SB, TGT, MD, HS, SSB