A client with myasthenia gravis has been receiving neostigmine and asks about its action. Which information would the nurse consider when formulating a response?

• A. Stimulates the cerebral cortex
• B. Blocks the action of cholinesterase
• C. Replaces deficient neurotransmitters
• D. Accelerates transmission along neural sheaths

Answer: (B)

The key idea here is how neostigmine enhances neuromuscular transmission in myasthenia gravis. Neostigmine is a reversible acetylcholinesterase inhibitor, meaning it blocks the enzyme that breaks down acetylcholine. By inhibiting acetylcholinesterase, more acetylcholine remains in the neuromuscular junction, increasing stimulation of the surviving nicotinic receptors and improving muscle contraction. This peripheral action helps compensate for the reduced receptor activity in MG and does not rely on triggering the cerebral cortex or directly replacing neurotransmitters. It also doesn’t speed conduction along the nerve’s myelin sheath.