The clinical pharmacology of mexiletine.

1. Mexiletine was given to 156 patients by intravenous or oral routes of administration. 2. There was great interpatient variation in kinetics and plasma concentrations with both routes of administration. 3. The mean volume of distribution was 6.63 l/kg. The mean plasma elimination haf-life after chronic oral therapy was 11.31 h. 4. Plasma concentrations between 0.75 and 2.00 microgram/ml were usually effective. Within this therapeutic range severe side effects were uncommon. 5. Plasma concentrations within this range were achieved in 72% of patients when doses of 10--14 mg-1 kg-1 day were given orally.