Sildenafil citrate as a medical expulsive therapy for distal ureteric stones: A randomised double-blind placebo-controlled study

Objective: To study the effect of sildenafil citrate on spontaneous passage of distal ureteric stones (DUS). Patients and methods: This was a randomised double-blinded placebo-controlled study of 100 patients with DUS. Inclusion criteria were: male, age 18–65 years, normal renal function, and a single radiopaque unilateral DUS of 5–10 mm. Patients were randomly allocated into two equal groups, one that received placebo and the other that received 50 mg sildenafil citrate once daily. Both investigators and patients were masked to the type of treatment. Patients self-administered the medication until spontaneous passage of the DUS. In patients where there was uncontrolled pain, fever, an increase in serum creatinine of 1.8 mg/dL, progressive hydronephrosis or no further progress after 4 weeks, a decision was taken for further treatment. Results: In all, 47 and 49 patients were available for analysis in both the placebo and sildenafil citrate groups; respectively. Both groups were comparable for age and stone characteristics. Spontaneous expulsion occurred in 19 of 47 patients (40.4%) in the placebo group and in 33 of 49 (67.3%) in the sildenafil citrate group (P = 0.014). The mean time to stone expulsion was significantly shorter in the sildenafil citrate group (P 0.001). A multivariable Cox proportional hazards model showed that receiving sildenafil citrate was the only independent factor that had a significant impact on stone passage with a hazard ratio of 2.7 (95% confidence interval 1.5– 4.8; P 0.001). Conclusion: Sildenafil citrate enhances spontaneous passage of 5–10 mm DUS.