Evaluating the Lidocaine's Initial Dosing in Patients With Ventricular Arrhythmias and Heart Failure Admitted in Intensive Care Units

Introduction Lidocaine is an antiarrhythmic with narrow therapeutic window indicated for refractory ventricular arrhythmia. Limited guidance is available regarding the initial infusion rate ranging from 1 to 4 mg/min in patients with heart failure (HF). Objectives The primary objective was to assess the optimal initial dosing of lidocaine therapy in patients with HF and ventricular arrhythmia. Methods The retrospective cohort study was performed to include patients aged 18 years or older with past medical history of HF or new onset HF who developed ventricular arrythmia requiring lidocaine therapy in cardiovascular intensive care units. The primary outcome was lidocaine levels within the therapeutic ranges (defined as 1.5 to 5.0 μg/L). The study also described the predictive performance of lidocaine one compartment PK model using correlation efficient between the population PK model‐predicted levels and observed levels. Results A total of 56 patients with HF and ventricular arrhythmia was included. The mean lidocaine maintenance dose was 1.1 ± 0.5 mg/min. The median (IQR) lidocaine level was 3.1 (2.3, 4.1) μg/L. The probabilities within therapeutic, supratherapeutic, and subtherapeutic ranges were 66.1%, 19.6%, and 14.3%, respectively in the whole cohort. Predicted lidocaine levels with one compartment PK model were not correlated with observed lidocaine levels ( R 2 = 0.34). The simulation investigation showed that 1 mg/min rate achieved the highest probability within therapeutic range compared to 0.5, 1.5, and 2.0 mg/min rates (78.6 vs. 53.6, 53.6, and 28.6%, respectively). Conclusion Lidocaine initial infusion rate should be up to 1 mg/min in patients with HF and ventricular arrhythmia.