Neostigmine antagonizes non-depolarizing blockade by all of the following mechanisms except.
Ans. (B) Preventing the K+ efflux from the cell(Ref: Katzung 10th/e p436; KDT 8th/e p375)Neostigmine is an anti-cholinesterase. It inhibits the breakdown of ACh at the motor end plate. This results in the increased activity of ACh that causes depolarization of motor end plate by opening Na+ channels (increasing the influx of Na+). It possesses some direct agonistic activity on NM receptors resulting in depolarization. In addition, a minor effect to increase the release of ACh at motor end plate is also present.
Decreasing the breakdown of acetylcholine at the motor end plate
Preventing the K+ efflux from the cell
Increasing the release of acetylcholine at the motor end plate
Depolarization at the motor end plate
Anaesthesia