Comparison of the antiarrhythmic activity of mexiletine and lorcainide on ventricular arrhythmias.
In a blind cross-over study, 12 patients with ventricular arrhythmias (VPC's; Lown Grades II-IVB) resistant to a daily dose of quinidine 1.2 g, disopyramide 0.8 g, N-propyl-ajmaline 0.1 g were randomly given, each dose for one week, placebo (PL), mexiletine (MEX; 400, 600, 800 mg daily) and lorcainide (LOR; 200, 300, 400 mg daily). On the last day of each treatment period, patients were evaluated by 24-h continuous ambulatory monitoring, 6-channel surface ECG, plasma concentrations and side-effects. During PL I (before) and PL II (after drug treatment), the mean number of VPCs per hour was 670 and 701. VPCs were reduced in 5 of the 12 patients with MEX by 43% (400 mg), 74% (600 mg) and 91% (800 mg). VPCs were reduced in 10 patients with LOR by 60% (200 mg), 78% (300 mg) and 93% (400 mg). Log. lin. plasma conc. effect relationships were constructed for MEX and LOR. Vomiting, nausea, and abdominal pain were seen in 2 patients with MEX; insomnia and feeling heat in 10 patients with LOR. At the end of the LOR-treatment, these side-effects were less in 5 and absent in 5 patients. In this study, LOR seems superior to MEX in refractory ventricular arrhythmias.
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000097:blood / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D044482:Benzeneacetamides; D002986:Clinical Trials as Topic; D003327:Coronary Disease / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000188:drug therapy; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008297:Male; D008801:Mexiletine / Q000097:blood / Q000627:therapeutic use*; D008875:Middle Aged; D008945:Mitral Valve Prolapse / Q000188:drug therapy; D010880:Piperidines / Q000097:blood / Q000627:therapeutic use*; D011437:Propylamines / Q000627:therapeutic use*; D011897:Random Allocation
D000889:Anti-Arrhythmia Agents; D044482:Benzeneacetamides; D010880:Piperidines; D011437:Propylamines; D008801:Mexiletine; C015970:lorcainide