Erectile Dysfunction 2: The Case of Mr. Powers' Limp MoJo
Mr. Powers develops erectile dysfunction after his radical prostatectomy for prostate cancer. You are expected to direct the evaluation, education, and management of this patient.
LEARNING OBJECTIVES for The Case of Mr. Powers' Limp MoJo
List and briefly describe the major etiologies of erectile dysfunction (ED)
List the important components of the history and physical examination of a patient with ED
List the treatment options for erectile dysfunction and describe the mechanisms by which these treatments work
Describe the indications, contra-indications and side-effects of phosphodiesterase inhibitors, such as sildenafil (Viagra)
Describe how to counsel a patient so that he uses phosphodiesterase inhibitors effectively
Mr. Powers Mourns his Limp MoJo
Mr. Powers is a 63-year old male who was diagnosed last year with moderately-differentiated prostate cancer found in a prostatic nodule. Desiring to "get that evil cancer out of my body," he underwent a radical prostatectomy. His prostate-specific antigen was 1.6 ng/ml at the time of diagnosis and has remained undetectable in the post-operative period thus far, consistent with complete excision of the tumor and prostate. While he is still able to have sex with his partners, his erections are now noticeably less firm than prior to the surgery. At times, he is unable to achieve vaginal penetration and becomes quite despondent that the surgery "took the go-go out of (his) MoJo." He requires the help of a Swedish vacuum device to get him a reasonable erection. Given that his erectile dysfunction is likely due to the effects of the radical prostatectomy, what is the specific mechanism of his ED? (Please select the single best answer.)
a. neurologic b. vascular c. hormonal d. infectious e. psychogenic
Mr. Powers Returns to his Urologist - 1
Mr. Powers returns to his urologist to report the difficulties with his MoJo and to ask what can be done to "heat things up." The urologist reviews Mr. Powers' past medical history: gunshot wounds, hypertension, and history of gallstones, liver damage from hallucinogenic chemicals, and multiple bouts of gonorrhea and genital warts. He is currently taking no medications. On physical examination, his surgical incision is well healed. He has a normal circumcised phallus with no evidence of deformity or fibrosis. The remainder of the examination is normal. The urologist discusses with Mr. Powers that he did perform a nerve-sparing radical prostatectomy, but even so, his erectile dysfunction is likely due to incidental nerve damage from the surgery. She suggests that Mr. Powers start an empiric trial of an oral phosphodiesterase inhibitor such as sildenafil (Viagra) to amplify any remaining function of the cavernous nerves. After confirming that there are no contra-indications for prescribing sildenafil to Mr. Powers, what instructions should the urologist give Mr. Power's regarding the effective use of sildenafil: (Please check all answers that apply.)
a. Take on an empty stomach to improve absorption b. Side effects include flushing, dyspepsia and a blue tint to one's vision c. Do not take Viagra if you are taking beta-blockers d. The effects of the drug last for 4-6 hours e. Stimulation is required to obtain an erection
Mr. Powers Returns to his Urologist - 2
Mr. Powers is disappointed to find that sildenafil (Viagra) does nothing for his erectile dysfunction, in spite of closely following all of the directions and titrating the dose upward. His urologist then discusses with him other treatment options. Which treatment options would be appropriate for Mr. Powers? (Please select all appropriate answers.)
a. Prostaglandin E1 injections b. Intra-urethral prostaglandin E1 c. Vacuum constriction device d. Malleable penile prosthesis e. Inflatable penile prosthesis
Mr. Powers' MoJo Rises Again!
Mr. Powers discusses the various treatment options with his partner and decides to continue treatment with his Swedish vacuum constriction device. He is extremely pleased with the device, although he notes that there can occasionally be some discomfort from the constrictive band which must be placed at the base of his penis to prevent the outflow of the blood. GROOVY, BABY!!
To be continued
Take-Home Messages - from The Case of Mr. Powers' Limp MoJo
Radical prostatectomy and radiotherapy (external beam or brachytherapy) can result in erectile dysfunction due to injury of the cavernous nerves which run just posterior and lateral to the prostate.
Treatment options for erectile dysfunction include oral phosphodiesterase inhibitors such as sildenafil (Viagra), intra-corporeal prostaglandin E1 injections, vacuum constriction devices, and surgical insertion of a malleable or inflatable penile prosthesis.
Side-effects of phosphodiesterase inhibitors such as sildenafil (Viagra) include flushing, headache, dyspepsia and a blue tint to one's vision.
Oral phosphodiesterase inhibitors such as sildenafil (Viagra) should be taken on an empty stomach one hour prior to sexual activity, require sexual stimulation to achieve an erection, and is effective for 4-6 hours.