Question

What does membrane expansion theory states?

(a) The mechanism is not similar to the general anesthetics

(b) Does not rely upon the lipophilic moiety of drugs

(c) The molecules of the agent get incorporated into the lipid membrane

(d) Causes nerve polarization

This question was addressed to me during a job interview.

The doubt is from Mechanism of Action of Local Anesthetic topic in section Local & General Anesthetics, Opioid Analgesics, Drug Addiction and Drug Abuse of Drug Biotechnology

Answer 1

The correct option is (c) The molecules of the agent get incorporated into the lipid membrane

Explanation: The membrane expansion theory depends upon the lipophilic moiety of local anesthetics agents. The molecules of the agent get incorporated into the lipid cell membrane which results in the swelling of the membrane. This provides physical obstruction of the sodium channels thus prevents nerve depolarization.