PDE-5: What the studies say
Of late, it has been quite a debate if certain PDE5 inhibitors are a form of treatment only suitable for people who underwent a RRP (Radical Retropubic Prostatectomy) and ended up losing their prostrate gland and therefore, their power to achieve an erection. Sildenafil scored the most amongst all other phosphodiesterase-5 inhibitors, namely Vardenafil and Tadalafil, despite them being a medicine of choice for the mass (read: general ED patients). The inferiority of the latter two is statistical and has proved one thing: That PDE-5 inhibitor must be selected according to a patient’s pattern of sexual activity, for at the end, a drug must be able to meet a patient’s expectations. Sildenafil wins hands down in this aspect and being prescribed for over 70% patients diagnosed clinically for ED, holds no doubt regarding its efficiency to hoist the flag of masculinity once more.
PDE-5 and Intra-operative Neurapraxia
A radical prostatectomy (surgical removal of part or all of the prostate gland) translates immediately to ED and applies to both types of erections (Psychogenic or emotional erections and nocturnal penile tumescence). This is a direct effect of intraoperative neurapraxia affecting the peripheral nervous system and normally takes anything between 18 and 24 months to recover. However, a comparative PDE-5 inhibitor oral therapy for people who underwent a retropubic prostatectomy showed the trabecular smooth muscle growing increasingly responsive as neurapraxia resolved and Sildenafil – as much dependent on the body’s nitric oxide production (from nerve endings) as other PDE-5 inhibitors – showing results after the first 6 months while the rest showed a rather low efficacy. This has made the term post-operative potency to be defined increasingly according to the response PDE-5 inhibitors provide. Sildenafil holds the highest score at 72% satisfaction rate.
A detailed study on Tadalafil:
The study was held on a total of 300 men (240 of them extremely satisfied with previous usage of Sildenafil) of mean age 60 years who presented normal erectile function preoperatively. 20 mg of Tadalafil produced a 41% (mean value) successful attempts at intercourse, whereas those given a placebo (an innocuous or inert medication; given as a pacifier or to the control group in experiments on the efficacy of a drug) presented a mere 19% success rate.
This proves Sildenafil an apt choice for them who underwent RRP while the other PDe-5 inhibitor is useful for general ED patients.
PDE-5: General Safety and Selectivity
By selectivity, we understand the differential ability for PDE-5 inhibition against the other members in the PDE family. Sildenafil and Vardenafil, at high doses, inhibit PDE-6 triggering visual disturbances, though not in an acute or chronic manner. This applies equally to people (men) with – normal visual function and those suffering from macular degeneration, non-proliferative diabetic retinopathy and being treated previously for glaucoma. However, Tadalafil has not been found inhibiting PDE-6 but PDE-11, an enzyme produced by the anterior pituitary, testicles, the prostate, the cardiac myocytes and by the cells forming the heart’s own conducting system, the results of which are still unknown. Tadalafil; however, increases the chances for muscle pain (in some cases) and still remains a matter of debate as much as its effect on normal testicular functions.
Do you need it?
Being of the on-demand kind and not the drugs meant for prolonged therapy or for daily dosing, PDE-5 inhibitors must be absolutely avoided if someone is an organic nitrates recipient. PDE-5 inhibitors interact with nitrates; for Sildenafil, the greatest risk is within 1 hour post-dosing and 48 hours for Tadalafil. PDE-5 inhibitors apart from Sildenafil are just primary prevention measures and lack substantial evidence, so a prior consultation with the doctor regarding one’s sexual activity pattern is highly suggested.
