In this study, we prospectively evaluated the effect of oral cimetidine on serum lidocaine concentrations in 6 patients with suspected myocardial infraction. Compared to baseline lidocaine levels, total lidocaine concentrations increased by 8.2 ± 7.8% at 6 hours, 16.4 ± 9.0% at 12 hours and 27.9 ± 9.4% at 24 hours after two doses of oral cimetidine. Unbound lidocaine concentrations increased by 14.3 ± 4.1% at 6 hours, and 18.3 ± 10.3% at 24 hours after cimetidine. In patients with myocardial infraction (3), total lidocaine concentrations increased by 24.2 ± 10.4%, whereas unbound lidocaine increased by 8.9 ± 10.2% at 24 hours. Therefore, increases in total lidocaine concentrations after cimetidine administration were considerably less than those previously reported and empiric dosage reductions of lidocaine in patients receiving cimetidine may not be appropriate.
- Drug interaction
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine