Old Habits Die Hard: a Nationwide Utilization Study of Short-acting Nifedipine in Taiwan

Background: To investigate the nationwide trend of ambulatory prescriptions of short-acting nifedipine on a PRN (pro re nata) order over a fifteen-year period in Taiwan.

Methods: The systematic sampling claims datasets (0.2% sampling ratio) of ambulatory care visits within Taiwan's National Health Insurance from 1997 to 2011 were analyzed. The prescriptions of short-acting capsule-form nifedipine on a PRN order were stratified by the patient's age, the prescribing physician's specialty, and the setting of healthcare facility for each year.

Results: During the study period, 8,189,681 visits were analyzed. While the utilization rate of calcium channel blockers changed with time from 2.8% (13,767/489,636) in 1997 to 5.1% (31,349/614,719) in 2011, that of short-acting nifedipine were from 1.0% (n = 5,070) to 0.2% (n = 1,246). However, short-acting capsule-form nifedipine on a PRN order still existed (from 447 prescriptions in 1997 to 784 in 2011). More than one half of these PRN nifedipines were prescribed by the internists and to the elderly patients; almost four-fifths of PRN nifedipines were prescribed during non-emergent consultations.

Conclusion: The physicians in Taiwan still had the habit of prescribing short-acting nifedipines for PRN use. The reason for such practices and the impact on patients' health deserve attention.