LidocaineDose, contraindications and adverse effects for Cats, Cattle, Dogs, Goats, Horses and Sheep.

Amide-type local anesthetic; used systemically by constant-rate infusion as an analgesic and antiarrhythmic adjunct. Besides its use as a local, regional, and topical anesthetic agent, lidocaine is frequently used to treat ventricular arrhythmias (eg, ventricular tachycardia, premature ventricular complexes [PVCs]) in all species.

Lidocaine is considered to be a class IB antiarrhythmic agent (membrane-stabilizing that shortens the myocardial cell action potential). Lidocaine acts by combining with inactive fast sodium channels, which inhibits recovery after repolarization.

Lidocaine is contraindicated in patients with known hypersensitivity to the amide-class local anesthetics, a severe degree of SA, AV, or intraventricular heart block (if not being artificially paced), Ad- ams-Stokes syndrome, and Wolff-Parkinson-White (WPW) syndrome. Cats tend to be more sensitive to the CNS and cardiodepressant effects of lidocaine; use with caution especially in cats with concurrent illnesses or under general anesthesia.

At usual doses, and if the serum concentration remains within the proposed therapeutic range (1 – 5 µg/mL), serious adverse effects are rare. The most common adverse effects reported are dose-related and mild. CNS signs include drowsiness, depression, ataxia, and muscle tremors. Nausea and vomiting may occur but are usually transient; the combination of sedation and vomiting may increase the risk for aspiration.

■ ECG, blood pressure, heart rate, pulse quality, pulse oximetry ■ Signs of toxicity (eg, depression, vomiting, nausea, ataxia, muscle tremors, PR and QRS interval prolongation, QT interval shortening, bradycardia, hypotension) ■ If available and indicated, serum lidocaine concentrations may be…