Local Anesthetics Lecture

These flashcards cover key concepts, mechanisms, clinical applications, and safety aspects of local anesthetics as discussed in the lecture notes.

What is the primary mechanism of action of local anesthetics?

Local anesthetics reversibly block fast voltage-gated Na+ channels in the neuronal membrane.

What are the two main classifications of local anesthetics?

Esters and amides.

How does the pH of inflamed tissue affect local anesthetic effectiveness?

Inflamed tissue has an acidic pH, increasing the proportion of cationic local anesthetic, which has low permeability, making anesthesia difficult to achieve.

What is the effect of adding sodium bicarbonate to local anesthetics?

It results in faster onset, reduced sting, and improved efficacy in inflamed tissue.

What is lidocaine commonly used for?

It is used for nerve blocks, surgery on standing animals, antiarrhythmic effects, and as an aid in preventing laryngeal spasm.

What is the risk of exceeding the maximum dose of local anesthetics?

CNS and cardiovascular effects, including seizures and potential death.

How do thin nerve fibers compare to thick ones in terms of susceptibility to local anesthetics?

Thin nerve fibers are more easily blocked than thick ones.

What is the significance of epinephrine when combined with local anesthetics?

Epinephrine decreases the rate of drug absorption and prolongs the effect of local anesthetics.

What are the advantages of using local anesthesia?

It allows surgical procedures on standing animals, requires no expensive equipment, is cost-effective, provides excellent pain control, and has minimal recovery time.

What is the main disadvantage of using cocaine as a local anesthetic?

It poses a significant potential for abuse.