Introduction. Lidocaine is the most common local anesthetic used in dentistry. The aim of the current study was to assess plasma concentrations of Lidocaine (buffered and non-buffered) and metabolite Monoethylglycinexylidide (MEGX). Materials and methods: The study included 45 healthy patients followed during mandibular nerve block and oral surgery interventions. The blood samples were taken 30 minutes after anaesthesia, and plasma levels were measured by liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode. Results and discussion: Median buffered lidocaine plasma levels (26 blood samples) at 30 minutes were 0.313±0.179 mg/L, while median non-buffered lidocaine plasma levels (19 blood samples) were 0.310±0.190 mg/L. Mean buffered monoethylglycinexylidide (MEGX) plasma levels (26 blood samples) at 30 minutes were 0.015± 0.013 mg/L, while mean non-buffered monoethylglycinexylidide (MEGX) plasma levels (19 blood samples) were 0.012±0.012 mg/L. Conclusions: No statistical difference in blood plasma levels between the mean values of buffered and non-buffered lidocaine and its metabolite monoethylglycinexylidide (MEGX) (p > 0.05) was observed.
Keywords:- buffering
- lidocaine
- liquid chromatography
- Monoethylglycinexylidide (MEGX)