Tocainide for drug-resistant ventricular arrhythmias: efficacy, side effects, and lidocaine responsiveness for predicting tocainide success.
Tocainide therapy has been evaluated in 38 patients with ventricular arrhythmias. Thirty-one had recurrent sustained ventricular tachycardia and/or fibrillation and 29 required prior cardioversions. These arrhythmias could not be managed with quinidine, procainamide, disopyramide, or propranolol. Tocainide doses averaged 1,500 mg/day (range 600 to 2,400) and the majority of patients had plasma concentrations from 6 to 12 micrograms/ml. Twenty-two patients (61%) had their arrhythmias controlled with tocainide and 16 (39%) did not. Tocainide dose and plasma concentrations were similar for responders and nonresponders. Lidocaine was effective in 26 patients and 16 (63%) of these had their arrhythmias controlled with tocainide. Of 12 patients in whom lidocaine was known to be ineffective or who had not been previously treated, only two (17%) had arrhythmias controlled with tocainide (P < 0.02). Side effects occurred in approximately two thirds of patients but required discontinuation of long-term tocainide in only three patients.
D000368:Aged; D000813:Anilides / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology; D006801:Humans; D008012:Lidocaine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000188:drug therapy; D016677:Tocainide; D014693:Ventricular Fibrillation / Q000188:drug therapy
D000813:Anilides; D016677:Tocainide; D008012:Lidocaine