dihydropyridines and Hemorrhage

The purpose of this study was to assess the effect of the dose of nifedipine, a dihydropyridine calcium antagonist, on the increased risk of mortality seen in the randomized secondary-prevention trials and to review the mechanisms by which this adverse effect might occur.. We restricted the dose-response meta-analysis to the 16 randomized secondary-prevention trials of nifedipine for which mortality data were available. Recent trials of any calcium antagonist and formulation were also reviewed for information about the possible mechanisms of action that might increase mortality. Overall, the use of nifedipine was associated with a significant adverse effect on total mortality (risk ratio, 1.16, with a 95% CI of 1.01 to 1.33). This summary estimate fails to draw attention to an important dose-response relationship. For daily doses of 30 to 50, 60, and 80 mg, the risk ratios for total mortality were 1.06 (95% CI, 0.89 to 1.27), 1.18 (95% CI, 0.93 to 1.50), and 2.83 (95% CI, 1.35 to 5.93), respectively. In a formal test of dose response, the high doses of nifedipine were significantly associated with increased mortality (P = .01). While the mechanism of this adverse effect is not known, there are several plausible explanations, including the established proischemic effect, negative inotropic effects, marked hypotension, recently reported prohemorrhagic effects attributed to antiplatelet and vasodilatory actions of calcium antagonists, and possibly proarrhythmic effects.. In patients with coronary disease, the use of short-acting nifedipine in moderate to high doses causes an increase in total mortality. Other calcium antagonists may have similar adverse effects, in particular those of the dihydropyridine type. Long-term safety data are lacking for most calcium antagonists.

Topics: Angina Pectoris; Arrhythmias, Cardiac; Calcium Channel Blockers; Confidence Intervals; Coronary Disease; Depression, Chemical; Dihydropyridines; Dose-Response Relationship, Drug; Hemorrhage; Humans; Hypotension; Myocardial Contraction; Myocardial Ischemia; Nifedipine; Odds Ratio; Renin-Angiotensin System; Sympathetic Nervous System; Time Factors

Outside of clinical trials, the prophylactic effect of dihydropyridine calcium channel blockers (CCBs) on ischemic events in patients with nonvalvular atrial fibrillation (NVAF) has not been confirmed. We compared the effect of dihydropyridine CCBs on ischemic events in anticoagulated NVAF patients. We conducted a multicenter historical cohort study at 71 centers in Japan. The inclusion criterion was taking vitamin K antagonists for NVAF. The exclusion criteria were mechanical heart valves and a history of pulmonary thrombosis or deep vein thrombosis. Consecutive patients (N = 7826) were registered in February 2013 and were followed until February 2017. The primary outcomes were ischemic events and ischemic strokes; the secondary outcomes were all-cause mortality, major bleeding, and hemorrhagic strokes. The mean patient age was 73 years old, and 67% of the patients were male. Seventy-eight percent of the patients had hypertension, and dihydropyridine CCBs were used by 2693 (34%) patients (CCB group). The cumulative incidences of ischemic events and ischemic strokes at 4 years in the CCB and No-CCB groups were 5.9% vs. 5.2% and 5.6% vs. 4.8%, respectively. The adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) of the CCB group for ischemic events and ischemic strokes were 1.22 (0.95-1.57) and 1.32 (1.02-1.71), respectively; the adjusted HRs (95% CIs) of the CCB group for all-cause mortality, major bleeding, and hemorrhagic strokes were 0.85 (0.69-1.04), 1.12 (0.92-1.35), and 1.08 (0.62-1.88), respectively. Dihydropyridine CCB use by anticoagulated NVAF patients significantly increased ischemic strokes in a real-world setting.

Topics: Aged; Anticoagulants; Atrial Fibrillation; Calcium Channel Blockers; Cohort Studies; Dihydropyridines; Female; Hemorrhage; Hemorrhagic Stroke; Humans; Ischemic Stroke; Male; Stroke