ABSTRACT
We compare plasma concentrations of mepivacine (MPV) and lidocaine (LDC) after epidural injection in 20 patients. Samples were drawn at 1, 5, 10, 15, 20, 60, and 120 minutes after administration. Absorption from epidural space is equally fast for both anesthetic agents (t max 20 +/- 7 minutes for MPV and 25 +/- 12 minutes for LDC) resulting in high values of Cmax: 7.8 +/- 3.3 microg/ml for MPV and 2.6 +/- 0.7 microg/ml for LDC (p less than 0.001). Mean values of K and Vd were 0.0076 +/- 0.0020 minutes-1 for MPV versus 0.0087 +/- 0.0032 minutes-1 for LDC and 0.9 +/- 0.7 1/kg for MPV versus 1.8 +/- 0.6 1/kg for LDC (p less than 0.001).
Subject(s)
Anesthesia, Epidural , Lidocaine/pharmacokinetics , Mepivacaine/pharmacokinetics , Adult , Aged , Female , Humans , Lidocaine/administration & dosage , Lidocaine/blood , Male , Mepivacaine/administration & dosage , Mepivacaine/blood , Middle AgedABSTRACT
The curves of lidocaine (LDC) plasma levels versus time were evaluated in a group of 16 patients receiving single epidural injections of 2% LDC for each metamer to be anesthesized. LDC absorption from epidural space is fairly rapid (tmax = 17 +/- 4 min and t1/2a = 6.2 +/- 1.7 min). This results in very shape peak plasma levels (2.97 +/- 0.87 micrograms/ml with 2% LDC). The remaining pharmacokinetic parameters were: Ke = 0.0057 +/- 0.0022 min-1 and Vd = 1.5 +/- 0.5 l/kg. In all patients adequate levels for operation were obtained.
