Low dose lidocaine combined with magnesium sulfate in warning ventricular arrhythmias

This study was designed to assess if low dose lidocaine (L) (0.8 mg/min at a constant rate infusion following a 100 mg bolus) combined with magnesium sulfate (M) (2.5 mg/min) controlled warning ventricular arrhythmias (a total of 119,806 ectopic beats and 146 runs of sustained ventricular tachycardia) in 7 (17%) out of 41 patients undergoing ambulatory monitoring. L alone was administered during the first 48 hours, then L+M for 48 hours, followed by L alone for a further 48 hours. Every 12 hours L serum levels were measured. Serum levels of L alone ranged from 0.33 to 2.06 mg/l (mean: 1.28 +/- 0.7 mg/l) during the first 48 hours and from 0.30 to 2.96 mg/l (mean: 1.24 +/- 1.02 during the last 48 hours). When the subjects received L+M, L serum levels were 0.69 to 3.28 mg/l (mean: 1.60 +/- 0.9 with p less than 0.05, statistically significant). Ambulatory monitoring also displayed a 70% reduction in warning ventricular arrhythmias during L+M treatment. L+M are more effective in the control of warning ventricular arrhythmias and we can also administer a lower dose of lidocaine when given in combination.