Local anesthetics are categorized based on their chemical structure.
Each class shares a common mechanism of action, primarily involving the inhibition of nerve impulse transmission.
Below is the classification along with the mechanism of action for each class:
1) Benzoic Acid Derivatives
Mechanism of Action: Block sodium channels by binding to the intracellular portion of the channel, preventing depolarization and nerve impulse conduction.
Examples: Cocaine, Hexylcaine, Meprylcaine, Cyclomethycaine, Piperocaine
2) Amino Benzoic Acid Derivatives
Mechanism of Action: Inhibit sodium ion influx by binding to sodium channels, thereby blocking nerve impulse transmission.
Examples: Benzocaine, Butamben, Procaine, Butacaine, Propoxycaine, Tetracaine, Benoxinate
3) Lidocaine/Anilide Derivatives
Mechanism of Action: Stabilize neuronal membranes by blocking voltage-gated sodium channels, which inhibits the initiation and conduction of nerve impulses.
Examples: Lignocaine (Lidocaine), Mepivacaine, Prilocaine, Etidocaine
4) Miscellaneous
Mechanism of Action: Primarily block sodium channels to prevent the propagation of nerve impulses, with varying affinities and durations of action.
Examples: Phenacaine, Diperodon, Dibucaine
Here is a shortened version of the table:
Classification | Examples | Mechanism | Uses | Side Effects |
Benzoic Acid Derivatives | Cocaine, Hexylcaine, Meprylcaine, Cyclomethycaine, Piperocaine | Block Na⁺ channels | Topical anesthesia, minor surgeries | Nervousness, tachycardia, hypertension, addiction risk |
Amino Benzoic Acid Derivatives | Benzocaine, Butamben, Procaine, Butacaine, Propoxycaine, Tetracaine, Benoxinate | Block Na⁺ channels | Surface anesthesia, minor procedures | Methemoglobinemia, allergic reactions, systemic toxicity |
Lidocaine/Anilide Derivatives | Lidocaine, Mepivacaine, Prilocaine, Etidocaine | Block Na⁺ channels | Dental work, surgeries, arrhythmias | CNS toxicity, cardiovascular issues, allergies |
Miscellaneous | Phenacaine, Diperodon, Dibucaine | Block Na⁺ channels | Various anesthesia uses | Varies: CNS/cardio toxicity, allergies |