Short-acting nifedipine and risk of stroke in elderly hypertensive patients

OBJECTIVES: Short-acting nifedipine is frequently prescribed in elderly hypertensive patients, despite warnings of possible harmful cardiovascular effects. We conducted a case-crossover study to estimate the risk of stroke episodes associated with use of short-acting nifedipine in elderly hypertensive patients. METHODS: We used the Korea Health Insurance Review & Assessment Service database. Cases included elderly hypertensive patients with hospitalization or emergency department visits for first stroke (International Classification of Diseases-10, I60-I64) between July 1, 2005, and June 30, 2006. Patients with prior stroke-related hospital admission or any visit related to TIA were excluded. Exposure to a short-acting nifedipine formulation was assessed within 7 days before the incident stroke episode (case period) and within a 7-day period preceding 60 days before the episode (control period). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by conditional logistic regression, with adjusting for antihypertensives, anticoagulants, antiplatelet agents, and pneumonia. RESULTS: A total of 16,069 stroke patients with a mean (±SD) age of 68.3 (±2.1) years were studied, of whom 8,573 (53.3%) were female. Short-acting nifedipine was prescribed at least once to 301 (1.9%) patients during the case period. An increased risk of stroke associated with use of short-acting nifedipine within 7 days (adjusted OR 2.56; 95% CI 1.96-3.37) was observed. Patients who were newly prescribed nifedipine within the recent 7 days showed an OR of 4.17 (95% CI 2.93-5.93) compared with nonusers. CONCLUSION: Use of short-acting nifedipine was associated with increased risk of stroke occurrence in elderly hypertensive patients.