Effects of vardenafil, a phosphodiesterase type-5 inhibitor, on sphincter of Oddi motility in patients with suspected biliary sphincter of Oddi dysfunction

BackgroundThe therapeutic approach in patients with sphincter of Oddi (SO) dysfunction (SOD) aims to reduce the resistance to the flow of bile or pancreatic juice. Vardenafil inhibits the activity of phosphodiesterase type 5 (PDE-5), which degrades cyclic guanossine monophosphate (cGMP) and results in relaxation of smooth muscle.ObjectiveThe present study was performed to determine the effects of vardenafil on SO motility in patients with suspected SOD.DesignProspective study.SettingsSingle university center.Patients and InterventionsTwenty consecutive adult patients with suspected SOD were scheduled to undergo ERCP and SO manometry by standard methods. A second recording was performed in the same position 20 minutes after administration of 10 mg vardenafil dissolved in 10 mL saline solution into the duodenum through a conventional catheter. SO pressures and motor function were compared in all patients with suspected SOD before and after administration of vardenafil.ResultsAfter administration of 10 mg of vardenafil, the mean basal sphincter pressure was reduced from 59.5 to 26.9 mm Hg (P < .001), and the mean phasic amplitude was reduced from 132.2 to 66.2 mm Hg (P < .001). The mean phasic wave frequency was not changed after administration of vardenafil (7.2/min vs 6.6/min, respectively, P = .07). These results did not differ between SOD types. No significant difference in manometric data were detected before and after administration of vardenafil between cholecystectomy and gallbladder in situ groups. Transient headache was observed in 1 patient, and the procedure-related complication was post-ERCP pancreatitis (n = 2 [10%]).LimitationsThe small sample size and uncontrolled study.ConclusionVardenafil inhibits SO motility in patients with suspected SOD and reduces basal SO pressure, without significant adverse effects.