Recainam dose titration and pharmacokinetics in patients with resistant arrhythmias

Recainam, a new antiarrhythmic drug, was evaluated in 20 patients with drug‐resistant stable ventricular arrhythmias. Dosage was increased stepwise every 48 to 72 hours until arrhythmia suppression, side effects, or a predetermined maximal dosage occurred. After a pharmacokinetic evaluation, efficacy was confirmed in a double‐blind, crossover protocol. One patient had unusable ambulatory ECG data. There were 14 of 19 patients who responded during dose titration; efficacy was confirmed in 11 of 14. The mean effective dosage and trough plasma concentration were 427 mg every 8 hours and 1.83 µg/ml, respectively. One patient withdrew because of nausea. Slowing of intraventricular conduction necessitated dosage reduction in two patients. Plasma half‐life was 9.4 ± 4.1 hours, with renal elimination accounting for 62% of oral clearance. However, 66% of the variability in oral drug clearance was the result of nonrenal elimination. Oral recainam at dosages of 300 to 600 mg every 8 hours is effective in some drug‐resistant ventricular arrhythmias and is well tolerated. Clinical Pharmacology and Therapeutics (1989) 46 , 324–334; doi: 10.1038/clpt.1989.146