Bupivacaine is a widely used local anesthetic agent. Bupivacaine is often administered by spinal injection prior to total hip arthroplasty. It is also commonly injected into surgical wound sites to reduce pain for up to 20 hours after surgery. In comparison to other local anesthetics it has a long duration of action. It is also the most toxic to the heart when administered in large doses. Bupivacaine blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibers. The analgesic effects of bupivicaine are thought to potentially be due to its binding to the prostaglandin E2 receptors, subtype EP1 (PGE2EP1), which inhibits the production of prostaglandins, thereby reducing fever, inflammation, and hyperalgesia. Bupivacaine sometimes used in combination with epinephrine to prevent systemic absorption and extend the duration of action.

Articaine is a dental local anesthetic, which is the most widely used in a number of European countries and is available in many countries around the world. Articaine in combination with epinephrine under the brand name Septocaine is indicated for local, infiltrative, or conductive anesthesia in both simple and complex dental procedures. Local anesthetics block the generation and conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rising of the action potential. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of the affected nerve fibers. Articaine blocks the actions on Na+ channels. Epinephrine is a vasoconstrictor added to articaine HCl to slow absorption into the general circulation and thus prolong maintenance of an active tissue concentration.

Ropivacaine is a member of the amino amide class of local anesthetics and is supplied as the pure S-(-)-enantiomer. It produces effects similar to other local anesthetics via reversible inhibition of sodium ion influx in nerve fibers. Ropivacaine is less lipophilic than bupivacaine and is less likely to penetrate large myelinated motor fibers, resulting in a relatively reduced motor blockade. Thus, ropivacaine has a greater degree of motor-sensory differentiation, which could be useful when the motor blockade is undesirable. The reduced lipophilicity is also associated with decreased potential for central nervous system toxicity and cardiotoxicity. Ropivacaine is indicated for the production of local or regional anesthesia for surgery and for acute pain management.

Prilocaine is a local anesthetic that is similar pharmacologically to lidocaine. Prilocaine binds to the intracellular surface of sodium channels which blocks the subsequent influx of sodium into the cell. Action potential propagation and never function is, therefore, prevented. This block is reversible and when the drug diffuses away from the cell, sodium channel function is restored and nerve propagation returns. Prilocaine acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Currently, Prilocaine is used most often for infiltration anesthesia in dentistry.

Mepivicaine is a local anesthetic of the amide type. Mepivicaine as a reasonably rapid onset and medium duration and is known by the proprietary names as Carbocaine and Polocaine. Mepivicaine is used in local infiltration and regional anesthesia. Systemic absorption of local anesthetics produces effects on the cardiovascular and central nervous systems. At blood concentrations achieved with normal therapeutic doses, changes in cardiac conduction, excitability, refractoriness, contractility, and peripheral vascular resistance are minimal. Mepivicaine is used for production of local or regional analgesia and anesthesia by local infiltration, peripheral nerve block techniques, and central neural techniques including epidural and caudal blocks.

Chloroprocaine (Nesacaine®, Nesacaine®-MPF) is a non pyrogenic local anesthetic. Nesacaine® is indicated for the production of local anesthesia by infiltration and peripheral nerve block. It is not to be used for lumbar or caudal epidural anesthesia. Nesacaine®-MPF is indicated for the production of local anesthesia by infiltration, peripheral and central nerve block, including lumbar and caudal epidural blocks. Nesacaine® and Nesacaine®-MPF are not to be used for subarachnoid administration. Chloroprocaine (Nesacaine®, Nesacaine®-MPF), like other local anesthetics, blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse and by reducing the rate of rise of the action potential. It acts mainly by inhibiting sodium influx through voltage gated sodium channels in the neuronal cell membrane of peripheral nerves. When the influx of sodium is interrupted, an action potential cannot arise and signal conduction is thus inhibited.

Proparacaine is a topical anesthetic drug of the amino ester group. It is available as its hydrochloride salt in ophthalmic solutions at a concentration of 0.5%. Proparacaine hydrochloride ophthalmic solution is indicated for procedures in which a topical ophthalmic anesthetic is indicated: corneal anesthesia of short duration, e.g. tonometry, gonioscopy, removal of corneal foreign bodies, and for short corneal and conjunctival procedures. Proparacaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action. More specifically, proparacaine appears to bind or antagonize the function of voltage gated sodium channels. The exact mechanism whereby proparacaine and other local anesthetics influence the permeability of the cell membrane is unknown; however, several studies indicate that local anesthetics may limit sodium ion permeability through the lipid layer of the nerve cell membrane. Proparacaine may alter epithelial sodium channels through interaction with channel protein residues. This limitation prevents the fundamental change necessary for the generation of the action potential.

Lidocaine is a local anesthetic and cardiac depressant used to numb tissue in a specific area and for management of cardiac arrhythmias, particularly those of ventricular origins, such as occur with acute myocardial infarction. Lidocaine alters signal conduction in neurons by blocking the fast voltage-gated Na+ channels in the neuronal cell membrane responsible for signal propagation. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarize and will thus fail to transmit an action potential. This creates the anesthetic effect by not merely preventing pain signals from propagating to the brain, but by stopping them before they begin. Careful titration allows for a high degree of selectivity in the blockage of sensory neurons, whereas higher concentrations also affect other modalities of neuron signaling. Lidocaine exerts an antiarrhythmic effect by increasing the electrical stimulation threshold of the ventricle during diastole. In usual therapeutic doses, lidocaine hydrochloride produces no change in myocardial contractility, in systemic arterial pressure, or an absolute refractory period. The efficacy profile of lidocaine as a local anesthetic is characterized by a rapid onset of action and intermediate duration of efficacy. Therefore, lidocaine is suitable for infiltration, block, and surface anesthesia. Longer-acting substances such as bupivacaine are sometimes given preference for spinal and epidural anesthesias; lidocaine, though, has the advantage of a rapid onset of action. Lidocaine is also the most important class-1b antiarrhythmic drug; it is used intravenously for the treatment of ventricular arrhythmias (for acute myocardial infarction, digoxin poisoning, cardioversion, or cardiac catheterization) if amiodarone is not available or contraindicated. Lidocaine should be given for this indication after defibrillation, CPR, and vasopressors have been initiated. A routine preventative dose is no longer recommended after a myocardial infarction as the overall benefit is not convincing. Inhaled lidocaine can be used as a cough suppressor acting peripherally to reduce the cough reflex. This application can be implemented as a safety and comfort measure for patients who have to be intubated, as it reduces the incidence of coughing and any tracheal damage it might cause when emerging from anesthesia. Adverse drug reactions (ADRs) are rare when lidocaine is used as a local anesthetic and is administered correctly. Most ADRs associated with lidocaine for anesthesia relate to administration technique (resulting in systemic exposure) or pharmacological effects of anesthesia, and allergic reactions only rarely occur. Systemic exposure to excessive quantities of lidocaine mainly result in a central nervous system (CNS) and cardiovascular effects – CNS effects usually occur at lower blood plasma concentrations and additional cardiovascular effects present at higher concentrations, though cardiovascular collapse may also occur with low concentrations.

Tetracaine (INN, also known as amethocaine; trade name Pontocaine. Ametop and Dicaine) is a potent local anesthetic of the ester group. It is mainly used topically in ophthalmology and as an antipruritic, and it has been used in spinal anesthesia. Tetracaine blocks sodium ion channels required for the initiation and conduction of neuronal impulses thereby affecting local anesthesia. In biomedical research, tetracaine is used to alter the function of calcium release channels (ryanodine receptors) that control the release of calcium from intracellular stores. Tetracaine is an allosteric blocker of channel function. At low concentrations, tetracaine causes an initial inhibition of spontaneous calcium release events, while at high concentrations, tetracaine blocks release completely.