Mexiletine kinetics in healthy subjects taking cimetidine.
Cimetidine, a commonly used H2-receptor antagonist, was found to interact adversely with many drugs, including class I antiarrhythmics such as lidocaine and quinidine. To test the effect of cimetidine on the kinetics of mexiletine, a class I antiarrhythmic similar to lidocaine, the absorption and disposition of mexiletine were followed in six healthy subjects before and after 1 week of cimetidine, 300 mg by mouth four times a day. Cimetidine did not alter the distribution and elimination of mexiletine, as shown by similar mean kinetics including total body clearance, AUC, and the elimination t1/2 before and after cimetidine treatment. Cimetidine did have a significant effect on mexiletine absorption, as demonstrated by a longer mean absorption t1/2 (from 0.20 +/- 0.14 to 0.61 +/- 0.35 hours), a longer mean time to peak mexiletine concentration (from 1.13 +/- 0.31 to 1.88 +/- 0.83 hours), and decreased mexiletine plasma concentration (from 0.74 +/- 0.19 to 0.59 +/- 0.15 mg/ml). We conclude that cimetidine does not alter the disposition of oral mexiletine in normal subjects.
D000042:Absorption; D000328:Adult; D002927:Cimetidine / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008801:Mexiletine / Q000378:metabolism*; D011437:Propylamines / Q000378:metabolism*; D013997:Time Factors
D011437:Propylamines; D008801:Mexiletine; D002927:Cimetidine