Journal of Dental Research, Vol 60, 1454-1459, Copyright © 1981 by International & American Associations for Dental Research Online Journals
Pharmacology of local anesthetic agents
B. G. Covino and D. B. Giddon
Local anesthetic agents may be classified according to their intrinsic
anesthetic potency and duration of activity. Procaine and chloroprocaine
are relatively weak, short-acting drugs. Lidocaine, mepivacaine, and
prilocaine represent agents of intermediate potency and duration of action.
Tetracaine, bupivacaine, and etidocaine are highly potent, long-acting
agents. The toxicity of local anesthetic drugs is usually due to
inadvertent rapid intravascular injection or extravascular administration
of an excessive amount. Intravascular toxicity is correlated with intrinsic
anesthetic potency, whereas toxicity following extravascular injections is
a function of physiological disposition characteristics of the various
agents, such as rate of vascular absorption, rate of tissue redistribution,
and rate of metabolism. The central nervous system is most susceptible to
the toxic effects of local anesthetic agents. Signs and symptoms of CNS
excitation followed by depression are the most common manifestations of
local anesthetic toxicity. Cardiovascular depression may also occur
following administration of excessive doses of local anesthetic agents or
following high spinal or epidural anesthesia.
