Nicorandil and diabetes: a nested case-control study to examine a signal generated by prescription-event monitoring

Objective: To investigate a signal generated by an observational cohort stu dy that treatment with the potassium channel opener drug, nicorandil, is as sociated with an increased incidence of diabetes mellitus (DM). Methods: Nested case-control study within cohorts used for prescription-eve nt monitoring. Results: The cohort study of nicorandil showed that there was a significant difference between the event rate for DM in the first month after starting nicorandil, compared to months 2-6 (difference in rates 1.93, 99% CI 0.7-3 .1, per 1000 patient months of treatment). However, the adjusted odds ratio from the case-control study was 1.42 (95% CI 0.66-3.07) for incidence of n ewly diagnosed DM in nicorandil versus four comparator drugs. Conclusions: The nested case-control study was used as a hypothesis-testing instrument for following up a signal of a possible drug reaction to nicora ndil. It showed no evidence that nicorandil is associated with increased in cidence of newly diagnosed DM.