Seasonal prevention of duodenal ulcer recurrences with pirenzepine.

Seasonal accumulation of duodenal ulcer recurrences suggests that maintenance therapy could be limited to the more risky periods. We carried out a 2-year, multi-centre, randomized, double blind study in 250 patients in whom the last ulcer proved to be healed at the endoscopy on entry. One-hundred-and-twenty-six patients in group A were given pirenzepine 2 X 25 mg while 124 in group B had 2 X 50 mg daily from the beginning of January to the end of March, and from the beginning of September to the end of November for two consecutive years. Test endoscopies were performed each year at the end of February, May and November. Both groups proved to be well comparable. Thirty-five patients dropped out from group A in the first and 10 in the second year; in group B 27 and 29, respectively. As the effect did not show any dose relation, the four yearly cycles were summarized. Recurrence rate checked in May was 22.1% while in both pirenzepine protected months it was 11.3% (p less than 0.0005) and 13.4% (p less than 0.001), respectively. We conclude that pirenzepine administered in the risky seasons prevents the peak ulcer incidence and reduces the recurrence rate to a level lower than in the non-risky season. Thus pirenzepine is effective in ulcer prevention even if administered in an interrupted manner.