3rd Annual Jefferson Urology Symposium: Men’s Health Forum

© The Canadian Journal of Urology TM : International Supplement, August 2020 Karakus AND Burnett as radical prostatectomy or other pelvic surgeries, due to lack of neuronal NO release. PDE5i are contraindicated in patients who are using nitrates due to leading potentially serious fall in systemic blood pressure. There is a possible drug-drug interaction betweenPDE5i and anti-hypertensive agents such as alpha-blockers or potent CYP3Ainhibitors such as azole antifungals, antiretroviral protease inhibitors, macrolide antibiotics, and anti-depressants. 17 The lowest possible starting dose should be prescribed, and the dosage should be titrated by close monitoring. 18 Although PDE5i possess different biochemical and pharmacologic properties, all have similar efficacy in the general ED population. Sildenafil and vardenafil are similar with regards to the duration of action being up to 10-12 hours, with a peak absorption of 30-60 minutes. Ahigh-fat meal decreases their efficacies, and the medication should be taken 1 hour before eating or 2 hours after eating to maximize absorption. Avanafil is absorbed in15-30minuteswithadurationof action for up to 6 hours. The half-life of tadalafil is longer (17 hours), and its duration of action is up to about 24-36 hourswith a longer onset of action of 60-120 minutes. Additionally, bothavanafil and tadalafil arenot affectedby food intake. Tadalafil is the onlyoralmedication approvedby theU.S. Food andDrugAdministration (FDA) to be useddaily to treat ED, aswell as to treat lower urinary tract symptoms in benign prostatic hyperplasia. Dose titration of PDE5i is a key step to providing optimal efficacy while minimizing adverse effects. The man and his partner should be counseled with administration of an initial treatment dose, whichmay need to be decreased to alleviate unacceptable adverse effects or increased due to inadequate response. The variations in dose-response effects across PDE5i medications are small, non-linear, and generally not clinically significant. However, a clinical trial comparing dose-response effects of sildenafil 10, 25, and 50 mg reported variations on hardness, frequency and duration of erections, and frequency of sexual intercourse. Still, none of these alternative dosages altered the number of attempts at intercourse. 19 When initiating treatment with PDE5i, the dosage can be chosen at mid-range; however, clinicians may consider initiating therapy at a higher dose for more severe ED when it is due to diabetes, radiation, or prostatectomy. On another note, penile rehabilitation with PDE5i remains unproven, and the early use of PDE5i following radical prostatectomy may not improve spontaneous unassisted erectile function. If the patient shows symptoms and signs of testosterone deficiencywith low total testosterone levels (< 300 ng/dL), PDE5i treatment for ED may require combination therapy with testosterone to improve its effectiveness. 20,21 Testosterone therapy is not sufficient for ED as a monotherapy; however, the restoration of testosterone levels likely supports themaximumefficacy of other ED treatment options. 22 Most adverse effects associated with the use of PDE5i are mild to moderate, includingdyspepsia, headache, flushing, backpain, nasal congestion, myalgia, visual disturbance, and dizziness. Vacuum erection device The VED is a mechanical device that is placed over the penis to generate a negative pressure to pull blood into the penis and cause an erection. A rubberized band is then placed around the base of the penis to maintain the erection during sexual intercourse. The device cost is low, and it is effective in men with ED associated with diabetes, spinal cord injury, post-prostatectomy, and other conditions. The satisfaction rate was reported up to 90%. However, the discontinuation rate was up to 30% due to pain and temporary changes to penile sensation due to the rubberized band, ejaculation problems, and bruising if the device is over pressurized. 23-26 Additionally, its use may be difficult for patients with insufficient dexterity or a large amount of lower abdominal fat and buried penis. Intraurethral alprostadil Alprostadil is an exogenous form of prostaglandin E1 (PGE1). Alprostadil, in the form of a urethral suppository, is delivered into the corpus cavernosum by direct diffusion or via collateral vessels. As a result, intracellular levels of cyclic AMP increase in corpus cavernosum smooth muscle cells, leading to penile erection. This route of administration is less invasive but less effective than ICI. However, it may be a good option for patients who do not prefer injectionmethods or cannot use oral medicationdue to contraindications. 27 Atest dose of medication should be administered in the clinic with patient to monitoring for hypotension and other possible adverse events such as penile pain and urethral burning. Additionally, instructions on the use of the urethral suppository can be given to the patient while titrating medication dose in the office. Intracavernosal injection A medication can directly be injected into the corpus cavernosum from the lateral base of the penis. Other injection sites are not preferable to avoid injecting the urethra in the ventral side and neurovascular bundle at thedorsal side. Papaverine, PGE1, andphentolamine are 30