BPH-associated LUTS and ED linked, one pill to treat both
Men with lower urinary tract symptoms (LUTS) are also found to be suffering from erectile dysfunction (ED), and studies show tadalafil 5 milligram once daily is safe and effective for the treatment of both LUTS due to benign prostate hyperplasia (BPH) plus coexisting ED.
It appears that the coexistence of the two conditions can not be explained by ageing alone as the underlying aetiology, said consultant urological surgeon and andrologist Mr. Asif Muneer, of the University College London Hospital, UK. [Eur J Gen Pract 2009;15(3):128–135] For instance, LUTS such as nocturia may result in poor sleep quality, leading to decreased sex drive and libido.
Link betweenBPH-associated LUTS and ED
There are four inter-related hypothesis on the shared pathophysiology of the two conditions; the nitric oxide/cyclic guanosine monophosphate pathway (NO/cGMP), pelvic atherosclerosis, Rho-kinase pathway and autonomic hyperactivity, explained Asif.
The NO/cGMP pathway plays a role in initiating and maintaining the relaxation of the corpus cavernosal smooth muscle. [J Urol 2003;170(2Pt2):S6-13] Elevated NO levels activate soluble guanylate cycles resulting in cGMP production and leading to a cascade of smooth muscle relaxation. Phosphodiesterase-5 (PDE5) inactivatesc GMP and is present in the prostate and bladder smooth muscle. [J Sex Med 2010;7:56–69, J Sex Med 2010;7:107–120] Thus, the NO/cGMP pathway is suggested to play a role in micturition and relaxation of the prostatic smooth muscle as well as erectile function.
ED and BPH-associated LUTS share several risk factors such as hypertension and smoking, where atherosclerosis is common, resulting in arterial insufficiency in the pelvic area and penis, said Asif. Chronic ischaemia can also cause fibrosis in the prostate and penile tissue, glandular cystic atrophy and increased smooth muscle contractility. [J Urol 2003;170(2Pt1):659–663]
Autonomic hyperactivity could also contribute to the development of ED and BPH-associated LUTS. It occurs in patients with metabolic syndrome, where there is abdominal obesity, dyslipidaemia, hyperglycaemia and hypertension with associated hyperinsulinaemia. As for the Rho-kinase pathway, it is suggested to be able toinhibit activation of endothelial NO synthase (NOS) and increase smooth muscle activity, contributing to both BPH-associated LUTS and ED. [Int J Impot Res 2002;14(1):1–7, J Urol 2003;170(6Pt1):2517–2522]
A single pill for both conditions
Pharmacotherapy for BPH-associated LUTS includes alpha blockers, 5-alpha reductase inhibitors and a combination these drugs. Both medications are effective but may cause the side effect of sexual dysfunction or ejaculatory dysfunction. To avoid that, healthcare professionals should identify patients with BPH-associated LUTS and coexisting sexual dysfunction or ED, and consider treating them with tadalafil 5 milligram once daily instead, said Asif.
Tadalafil 5 milligram has the advantage of allowing spontaneity in a patient’s sexual life as it can be taken in a once daily dose, said Asif.It has a long half-life of 17.5 hours and duration of action of 36 hours. [Br J Clin Pharmacol 2006;61(3):280–288] It is patient-friendly as its absorption is not affected by consumption of high fat meals and alcohol.
Tadalafil’s long term effectivenessis established and there is no formation of tolerance or treatment resistance. As for its safety, the risk of cardiovascular events is minimal and adverse events are mild to moderate in severity. [Am J Cardiol 2006;97(12):1778–1784, Korean J Urol 2012;53(6):377–385]
Asif was speaking at the launch of Cialis® once-a-day, organized by Eli Lilly, held in Kuala Lumpur recently.