O1036: Safety and Tolerability of Super Selective alpha-1 Adrenergic Blockers in Children Under the Age of 3 Years: Prospective Experience in Patients with Posterior Urethral Valves (PUV)

Background: Selective alpha-blockers, commonly prescribed for treatment of lower urinary tract symptoms caused by benign prostatic hyperplasia (BPH), are oftentimes used off-label in young infants based on low-level evidence. Therefore, we aim to assess the safety and tolerability of selective alpha-blockers in children with posterior urethral valves (PUV) under the age of 3 years.

Methods: A prospectively-collected database captured 91 PUV patients born between 12/2005 and 01/2023. Assessed data included baseline characteristics, ultrasound, features, blood pressure, side effects and creatinine values. Primary outcome was occurrence of side effects or discontinuation of alpha-blockers. Secondary outcomes blood pressure parameters, growth, and kidney function. Data are shown as median with interquartile range (IQR), Odds Ratio (OR) with 95% CI and mean value with standard deviation (SD).

Results: A total of 33 patients less than 3 years of age were started on alpha-blockers at mean age of 16.8+/-11.8 months and followed for 48.9+/- 40.5 months. At last follow-up, no significant effect on systolic and diastolic blood pressure percentiles (p=0.9974 and p=0.9994), creatinine levels (p=0.9712) or right/left PI-APD was observed. Weight percentiles increased to the last follow-up (37.8+/- 33.2 vs. 53.6+/- 32.9, p=0.0133) while height percentiles increased from 28-100 days to last follow-up (12.9+/-18.3 vs. 39.6+/-35.2, p=0.0012). 10 patients discontinued alpha-blockers; however, no side-effects were reported during the study period. Overall effect estimates demonstrated significantly decreased odds of SFU3-4 HN after 28-100 days (OR 2.525; 95% CI 1.162-5.354; p=0.0318) and at last follow-up (OR 3.02; 95% CI 1.357-6.687; p=0.0105).

Conclusion: No severe clinical or systemic side effects were observed, demonstrating safety and tolerability in young children with PUV. Although alpha-blockers did not significantly improve kidney function in short term follow-up. Additional studies with more patients are required to assess the optimal dosing and timing leading to maximal benefits for these infants.