Local anesthetics are drugs that block nerve conduction when applied locally to nerve tissue in appropriate concentrations. Their action is completely reversible. They act on every type of nerve fibre and can cause both sensory and motor paralysis in the innervated area. The primary mechanism of action is blockade of voltage gated sodium channels. Depending on the concentration attained in the plasma, any LA can produce systemic effects. Local anesthetics are rapidly absorbed from the mucous membranes and abraded skin. Hypersensitivity reactions, hypotension, confusion, disorientation, anxiety, convulsions and respiratory failure can result from large doses. Depending on the site and technique of the administration LA can be surface anesthesia, infiltration anesthesia, field block, nerve block, spinal, epidural or intravenous regional anesthesia.