Effect of nifedipine on sphincter of Oddi motor activity: studies in healthy volunteers and patients with biliary dyskinesia.

The effect of nifedipine on sphincter of Oddi (SO) motor activity was determined by endoscopic manometry. Sphincter of Oddi pressures and motor function were compared in 21 healthy volunteers and in 9 patients with SO dyskinesia. The effects of sublingual doses of 10 or 20 mg of nifedipine were compared with placebo. Neither placebo nor 10 mg of nifedipine produced any effect on SO motor activity. In healthy volunteers 20 mg of nifedipine produced a moderate but significant decrease in basal SO pressure from 12.0 to 6.7 mmHg as well as in the amplitude, duration, and frequency of phasic contractions. In patients with SO dyskinesia 20 mg of nifedipine also resulted in a significant but more profound decrease of the basal SO pressure from 47.1 to 17.3 mmHg as well as in a decrease of amplitude, duration, and frequency of the phasic contractions. Neither placebo nor 10 or 20 mg of nifedipine has any effect on the sequence of phasic contractions. In summary, nifedipine may have a possible therapeutic role in the treatment of SO dyskinesia.