Regional distribution of 11C-labeled lidocaine, bupivacaine, and ropivacaine in the heart, lungs, and skeletal muscle of pigs studied with positron emission tomography.
The regional myocardial uptake and kinetics of 11C-lidocaine, 11C-bupivacaine, and 11C-ropivacaine were examined in the pig, utilizing positron emission tomography to determine whether disproportionate distribution exists among these agents. The three drugs were rapidly distributed to the myocardium and lung with mean peak radioactivities occurring between 0.35 and 0.48 min post-injection in myocardium and 0.35 and 0.65 min in lung. Radioactivities peaked later in skeletal muscle than in the myocardium and lung, occurring between 1.1 and 2.7 min post-end injection. Blood radioactivities for bupivacaine and ropivacaine were significantly higher than those of lidocaine, whereas myocardial, lung, and muscle uptakes for the three agents were not significantly different. Myocardium-blood partition coefficients were similar for bupivacaine and ropivacaine (0.55 and 0.49 respectively), while it was three times higher for lidocaine (1.4). A similar relationship existed for skeletal muscle- and lung-blood partition coefficients. Bupivacaine and ropivacaine t1/2z in skeletal muscle were significantly longer than those of lidocaine. The results of this study indicate that the increased cardiotoxicity associated with bupivacaine does not appear to be related to disproportionate distribution in the myocardium when compared to lidocaine and ropivacaine.
Feldman
H S
HS
Department of Anesthesia Research Laboratories, Brigham and Women's Hospital, Boston, MA, USA.
Hartvig
P
P
Wiklund
L
L
Doucette
A M
AM
Antoni
G
G
Gee
A
A
Ulin
J
J
Langstrom
B
B
D000577:Amides / Q000493:pharmacokinetics; D000779:Anesthetics, Local / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D002045:Bupivacaine / Q000493:pharmacokinetics; D002250:Carbon Radioisotopes; D006207:Half-Life; D007275:Injections, Intravenous; D008012:Lidocaine / Q000493:pharmacokinetics; D016014:Linear Models; D008168:Lung / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D000077212:Ropivacaine; D013552:Swine; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed
D000577:Amides; D000779:Anesthetics, Local; D002250:Carbon Radioisotopes; D000077212:Ropivacaine; D008012:Lidocaine; D002045:Bupivacaine