Lignox A 2% Injection is a combination medicine used as local anesthesia. It blocks pain signals from the nerves to the brain thereby decreasing the sensation of pain.

Composition:-
Lidocaine Hydrochloride and Adrenaline, is a sterile isotonic solution containing a local anesthetic agent, Lidocaine Hydrochloride, and a vasoconstrictor, Adrenaline (as bitartrate) and are administered parenterally by injection.
The solutions contain lidocaine hydrochloride which is chemically designated as acetamide, 2-(diethylamino)-N-(2,6-dimethylphenyl)-monohydrochloride. Adrenaline is ( - )-3,4-Dihydroxy-α-[(Methylamino) methyl] benzyl alcohol.

Mechanism of Action:-
Lidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of nerve impulses, thereby effecting local anesthetic action.

Pharmacokinetics:-
When used for infiltration anesthesia in dental patients, the time of onset averages less than two minutes for Lidocaine and Epinephrine Injections. Lidocaine and Epinephrine Injections provide an average pulp anesthesia of at least 60 minutes with an average duration of soft tissue anesthesia of approximately 2½ hours. When used for nerve blocks in dental patients, the time of onset for both forms of Lidocaine and Epinephrine Injections averages 2 - 4 minutes. Lidocaine and Epinephrine Injections provide pulp anesthesia averaging at least 90 minutes with an average duration of soft tissue anesthesia of 3 to 3½ hours.

Absorption and Metabolism:-
concentrations and usages reveals that lidocaine is completely absorbed following parenteral administration, The plasma binding of lidocaine is dependent on drug concentration, and the fraction bound decreases with increasing concentration. At concentration of 1 to 4 μg of free base per mL, 60 to 80 percent of lidocaine is protein bound. Binding is also dependent on the plasma concentration of the alpha-l-acid glycoprotein. Lidocaine crosses the blood-brain and placental barriers, presumably by passive diffusion.

Lidocaine is metabolized rapidly by the liver, and metabolites and unchanged drug are excreted by the kidneys.
Studies of lidocaine metabolism following intravenous bolus injections have shown that the elimination half-life of this agent is typically 1.5 to 2.0 hours. Because of the rapid rate at which lidocaine is metabolized, any condition that affects liver function may alter lidocaine kinetics.

Indications:-
Lidocaine and Epinephrine Injection, USP is indicated for the production of local anesthesia for dental procedures by nerve block or infiltration techniques.

Contraindications:-
Lidocaine and Epinephrine Injections is contraindicated in patients with a known history of hypersensitivity to local anesthetics of the amide type or to any components of the injectable formulations.