Background: Amiodarone (AMD), nifekalant (NIF), and lidocaine (LID) hydrochlorides are widely used for ventricular tachycardia/fibrillation (VT/VF). This study retrospectively investigated the NIF potency and the differential effects of 2 initial AMD doses (≤150 mg or 300 mg) in the Japanese SOS-KANTO 2012 study population.
Methods and results: From 16,164 out-of-hospital cardiac arrest cases, 500 adult patients using a single antiarrhythmic drug for shock-resistant VT/VF were enrolled and categorized into 4 groups (73 LID, 47 NIF, 173 AMD-≤150, and 207 AMD-300). Multivariate analyses evaluated the outcomes of NIF, AMD-≤150, or AMD-300 groups versus LID group. Odds ratios (ORs) for survival to admission were 3.21 [95% confidence interval (CI): 1.38-7.44, P < 0.01] in NIF and 3.09 (95% CI: 1.55-6.16, P < 0.01) in AMD-≤150 groups and significantly higher than those of the LID group. However, the OR was 1.78 (95% CI: 0.90-3.51, P = 0.10) in AMD-300 group and was not significant than LID group. ORs for 24-hour survival were 6.68 in NIF, 4.86 in AMD-≤150, and 2.97 in AMD-300, being significantly higher in these groups.
Conclusions: NIF and AMD result in similar improvements for 24-hour survival in cardiopulmonary arrest patients, and this suggest the necessity of a randomized control study.