st, and cardiovascular stimulation or depression have been reported.
These reactions may be due to intra-arterial injection of the local anesthetic with retrograde flow to the cerebral circulation. Patients
receiving these blocks should have their circulation and respiration monitored and be constantly observed. Resuscitative equipment
and personnel for treating adverse reactions should be immediately available. Dosage recommendations should not be exceeded (see
DOSAGE AND ADMINISTRATION).
Information for Patients
When appropriate, patients should be informed in advance that they may experience temporary loss of sensation and motor activity,
usually in the lower half of the body, following proper administration of epidural anesthesia.
Clinically Significant Drug Interactions
The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase
inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension.
Phenothiazines and butyrophenones may reduce or reverse the pressor effect of epinephrine.
Concurrent use of these agents should generally be avoided. In situations when concurrent therapy is necessary, careful patient
monitoring is essential.
Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic
drugs may cause severe, persistent hypertension or cerebrovascular accidents.
Drug/Laboratory Test Interactions
The intramuscular injection of lidocaine HCl may result in an increase in creatine phosphokinase levels. Thus, the use of this enzyme
determination, without isoenzyme separation, as a diagnostic test for the presence of acute myocardial infarction may be compromised
by the intramuscular injection of lidocaine HCl.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Studies of lidocaine HCl in animals to eva luate the carcinogenic and mutagenic potential or the effect on fertility have not been
conducted.
Pregnancy
Teratogenic Effects: Pregnancy Category B. Reproduction studies have been performed in rats at doses up to 6.6 times the
human dose and have revealed no evidence of harm to the fetus caused by lidocaine HCl. There are, however, no adequate and
well-controlled studies in pregnant women. Animal reproduction studies are not always predictive of human response. General
consideration should be given to this fact before administering lidocaine HCl to women of childbearing potential, especially during
early pregnancy when maximum organogenesis takes place.
Labor and Delivery
Local anesthetics rapidly cross the placenta and when used for epidural, paracervical, pudendal or caudal block anesthesia, can
cause varying degrees of maternal, fetal and neonatal toxicity (see CLINICAL PHARMACOLOGY, Pharmacokinetics and
Metabolism). The potential for toxicity depends upon the procedure performed, the type and amount of drug used, and the technique
of drug administration. Adverse reactions in the parturient, fetus and neonate involve alterations of the central nervous system,
peripheral vascular tone and cardiac function.
Maternal hypotension has resulted from regional anesthesia. Local anesthetics produce vasodilation by blocking sympathetic nerves.
Elevating the patient’s legs and positioning her on her left side will hel
