Local Anesthetic Agents

Which of the following local anesthetic agents is an example of an ester?

Which of the following pharmacological properties of local anesthetics affects the duration and potency of the anesthetic?

What is the primary mechanism of action of local anesthetic agents?

Which local anesthetic agent has a higher risk of cardiac toxicity?

What is the term for the time it takes for the anesthetic to take effect?

Which of the following is a rare side effect of certain local anesthetics?

What is the term for the dose required to produce effective anesthesia?

What is the term for the length of time the anesthetic remains effective?

Which local anesthetic agent is a combination of amino amide and ester structures?

Which of the following local anesthetics has a fast onset and medium duration?

Local Anesthetic Agents

Classification

Amino Amides:
- Most commonly used local anesthetics
- Examples: lidocaine, mepivacaine, prilocaine, articaine
Esters:
- Older local anesthetics, less commonly used
- Examples: tetracaine, benzocaine, procaine
Amphipathic:
- Combination of amino amide and ester structures
- Example: ropivacaine

Mechanism of Action

Local anesthetics work by blocking the generation and conduction of nerve impulses
They bind to the alpha subunit of the sodium channel, preventing the influx of sodium ions
This prevents the nerve from depolarizing and transmitting pain signals

Pharmacological Properties

Potency: measured by the dose required to produce effective anesthesia
Duration: length of time the anesthetic remains effective
Onset: time it takes for the anesthetic to take effect
Protein binding: affects the duration and potency of the anesthetic
Lipid solubility: affects the anesthetic's ability to penetrate the nerve membrane

Individual Local Anesthetics

Lidocaine:
- Most commonly used local anesthetic
- Fast onset, medium duration
- Used for infiltration, nerve block, and epidural anesthesia
Bupivacaine:
- Long-acting local anesthetic
- Used for epidural and spinal anesthesia
- Has a higher risk of cardiac toxicity
Mepivacaine:
- Intermediate-acting local anesthetic
- Used for infiltration, nerve block, and epidural anesthesia
- Has a faster onset than bupivacaine

Adverse Effects

Allergic reactions: rare, but can be severe
Systemic toxicity: can cause CNS and cardiac effects
Methemoglobinemia: a rare side effect of certain local anesthetics

This quiz covers the classification, mechanism of action, pharmacological properties, and adverse effects of local anesthetic agents, including examples such as lidocaine, bupivacaine, and mepivacaine.