• The route of administration of most local anesthetics is injection.

What drug is local anaesthetic?

• Commonly used amino amides include lidocaine, mepivacaine, prilocaine, bupivacaine, etidocaine, and ropivacaine and levobupivacaine.

what is mechanism of local anesthetics?

Local anesthetics work by blocking nerve conduction in a reversible manner, thereby preventing the sensation of pain or other stimuli in a localized area. Here's how they achieve this:

1. Blocking Sodium Channels: Local anesthetics primarily act by blocking voltage-gated sodium channels on the neuronal cell membrane. These channels are responsible for the influx of sodium ions that initiate and propagate action potentials (nerve impulses). By binding to these channels and inhibiting sodium influx, local anesthetics prevent the generation and propagation of action potentials along the nerve fibers.

2. Membrane Stabilization: When a local anesthetic binds to the sodium channel, it stabilizes the channel in an inactive state. This prevents the channel from reopening and participating in the depolarization necessary for action potential propagation.

3. Nerve Fiber Selectivity: Local anesthetics can affect different types of nerve fibers (e.g., Aδ and C fibers) depending on their properties. Small nerve fibers (like those responsible for pain sensation) are often more sensitive to local anesthetics compared to larger fibers responsible for touch or motor function.

4. Route of Administration: Local anesthetics can be administered via various routes such as topical application, infiltration (direct injection into tissue), nerve block (injection near a specific nerve), or epidural/spinal injection. The choice of route depends on the desired duration and depth of anesthesia.

5. Duration of Action: The duration of anesthesia provided by a local anesthetic depends on factors such as its lipid solubility, protein binding, metabolism, and vascularity of the injection site. Some local anesthetics are metabolized by enzymes in the body, while others are excreted unchanged in the urine.

Overall, the mechanism of action of local anesthetics involves interfering with the initiation and propagation of nerve impulses, leading to temporary loss of sensation in the localized area where they are applied or injected.

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