Background: Sildenafil was reported to have a strong inhibitory effect on both gallbladder contraction and biliary pressure of the Sphincter of Oddi. We hypothesized that a single oral dose of sildenafil might counteract the smooth muscle spasm and decrease the intra-ductal and sphincteric pressures to relieve the pain of biliary colic and facilitate the release of impacted stones. Objectives: To assess the pain-relieving effect of 25 mg oral Sildenafil dose in comparison to an oral 20 mg ketorolac dose in adult patients presenting with acute biliary colic. Methods: Twenty consecutive eligible patients presenting with moderate to severe biliary colic were randomly assigned to receive one Sildenafil 25 mg tablet or two ketorolac 10 mg oral tablets. A four-point verbal rating scale (VRS) and 100 mm Visual pain analog scale (VPAS) of pain severity were measured before treatment then at 30 and 60 minutes after the dose intake. Results: Treatment success, defined as a reduction of VRS, 60 minutes after dose intake from moderate and severe to mild or none was similar (9/10) in both treatment groups. Significant reductions of VPAS at 30 and 60 minutes were noted in both groups. The reduction in VPAS after 60 minutes from dose intake was significantly greater in the Sildenafil group (83.16%) than in the ketorolac group (79.34%) (p=0.033). Conclusions: Single oral dose of sildenafil 25 mg might be safe and effective for the relief of biliary colic. Further studies are needed to confirm its value, particularly for patients who cannot tolerate or show inadequate response to NSAIDs or opiates.

The authors have declared no competing interest.

ACTRN12619001388101 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378014&isReview=true)

This study did not receive any funding

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