ATC Group: S01H Local anesthetics

Chloroprocaine is procaine in which one of the hydrogens ortho- to the carboxylic acid group is substituted by chlorine. Chloroprocaine, 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. Chloroprocaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine.

Cinchocaine is a local anaesthetic agent and is suitable for surface or spinal anaesthesia and for relaxing sphincteric spasms. It is an anaesthetic of the amide type. It is more toxic than cocaine by local application but its local anaesthetic action is greater so it can be used in lower concentrations. Its action is more prolonged than lignocaine.

Cocaine is a tropane alkaloid with central nervous systems (CNS) stimulating and local anesthetic activity. Cocaine binds to the dopamine, serotonin, and norepinephrine transport proteins and inhibits the re-uptake of dopamine, serotonin, and norepinephrine into pre-synaptic neurons. This leads to an accumulation of the respective neurotransmitters in the synaptic cleft and may result in increased postsynaptic receptor activation. The mechanism of action through which cocaine exerts its local anesthetic effects is by binding to and blocking the voltage-gated sodium channels in the neuronal cell membrane. By stabilizing neuronal membranes, cocaine inhibits the initiation and conduction of nerve impulses and produces a reversible loss of sensation.

Lidocaine, like other local anaesthetics, causes a reversible blockade of impulse propagation along nerve fibres by preventing the inward movement of sodium ions through the nerve membrane. Local anaesthetics of the amide-type are thought to act within the sodium channels of the nerve membrane.

Procaine is a benzoic acid derivative with local anesthetic and antiarrhythmic properties. Procaine binds to and inhibits voltage-gated sodium channels, thereby inhibiting the ionic flux required for the initiation and conduction of impulses. In addition, this agent increases electrical excitation threshold, reduces rate of rise of action potential and slows nerve impulse propagation thereby causing loss of sensation. Procaine is indicated for production of local or regional anesthesia, particularly for oral surgery. Procaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine.

Proxymetacaine is a potent topical anaesthetic of the ester type. The main site of anaesthetic action is the nerve cell membrane where proxymetacaine interferes with the large transient increase in the membrane permeability to sodium ions that is normally produced by a slight depolarisation of the membrane.

Tetracaine is a local anaesthetic and is believed to act by blocking nerve conduction mainly by inhibiting sodium ion flux across the axon membrane.