EAU 2018: Is Medical Expulsive Therapy (MET) With Tadalafil More Effective Than Tamsulosin In Distal Ureteric Stones (DUS)?ِ A Prospective Randomized Study

Copenhagen, Denmark (UroToday.com) 22% of all urinary tract stones are found in the ureter, of which 68% of these are found in the distal ureter. A popular technique of conservative management for patients with distal ureter stones is medical expulsive therapy (MET), or the use of pharmaceuticals to facilitate spontaneous stone passage. In particular, because the distal third of the ureter is heavily concentrated in a1adreneric receptors, the blockage of these receptors with alpha1 blockers selectively relaxes the ureteric smooth muscle and dilates the ureteric lumen. The selective pharmaceutical of choice, therefore, is the use of a PDE-5 inhibitor such as that of tadalafil.

Dr. Boulos (MD) of El Sahel Teaching Hospital in Cairo Egypt, presents an open-label prospective randomized study to compare the safety and efficacy of tadalafil (Cialis) and tamsulosin (Flomax) for distal ureteric stones (DUS) ≤1cm. 106 patients were enrolled, with a final 100 (50 in each arm: 0.4mg tamsulosin versus 10mg tadalafil) patients included in analysis. Both groups were followed for 12 months, of which the drug was continued until spontaneous stone passage or, alternatively, for 4 weeks. Between the two arms of the studies, there were no statistically significant differences in regards to covariates such as age, sex, stone site, and size.

The primary outcome measure was stone clearance rate, of which was 84% in the tadalafil group reached versus 64% in the tamsulosin group (p=0.040). Similarly, the secondary outcome measure was time to stone expulsion was also significantly shorter in the tadalafil group (14.5 days versus 17.2 days, p<0.001). Safety was confirmed in both groups, as there were no serious adverse effects or side effects in either arm.

Overall, Dr. Boulos asserts that tadalafil (Cialis) is a safe alternative to tamsulosin (Flomax) in this patient cohort as it increases ureteric stone clearance and shortens the time to stone expulsion. In discussion, tadalafil was specifically chosen as an alternative to tamsulosin as it has the longest duration of action in the body and is unaffected by meal cycles or circadian rhythms. Additionally, lower doses of tadalafil have also been shown to be effective for management of urinary continence symptoms via similar mechanisms of ureteric smooth muscle relaxation and ureteric lumen dilation.

However, as a supplement to these study results, Dr. Boulos also notes that 50% of stones were spontaneously passed without use of MET. Perhaps, he mentions, PDE-5 and a1adreneric therapies can be combined to yield a synergistic effect via their two unique mechanisms that may further benefit patients with stones in the distal ureter.

Speaker: Dr. Boulos

Authors: Boulos V., Nada A.

Written by: Linda M. Huynh, University of California-Irvine, at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark