Efficacy of nifedipine therapy in patients with sphincter of Oddi dysfunction: a prospective, double-blind, randomized, placebo-controlled, cross over trial.

1. Twenty-eight patients who fulfilled entry criteria for sphincter of Oddi dysfunction were randomly allocated to receive nifedipine and placebo in a cross over design with 12 week treatment periods separated by a 2 week wash-out. 2. All patients had episodic pain resembling biliary pain, had previously undergone cholecystectomy, had elevated alkaline phosphatase during episodes of pain and had elevated basal pressure on sphincter of Oddi manometry. 3. Compared with placebo, significant decreases in cumulative pain score, number of pain episodes, oral analgesic tablets consumed and emergency room visits were observed during nifedipine treatment. 4. Overall 21 patients improved during nifedipine therapy while seven patients did not. None of the following predicted response to nifedipine therapy: enzyme levels, morphine-Prostigmine test, fatty meal sonography, common duct diameter and pressure, sphincter of Oddi phasic pressure, frequency and duration of phasic waves and maximal fall in the basal pressure at sphincter of Oddi manometry after sublingual administration of nifedipine. However patients with predominant antegrade propagation of phasic contractions of sphincter of Oddi did significantly better on nifedipine than those with abnormal propagation of phasic contractions. 5. Nifedipine therapy orally in maximal tolerated doses relieves pain in patients with sphincter of Oddi dysfunction who have elevated basal pressure and sphincter of Oddi phasic contractions of predominantly antegrade nature.