A patient complains of muscle weakness. It was reversed on administration of neostigmine, because:

Ans. (D) It interferes with the action of acetyl cholinesterase(Ref: Katzung 11/e p105)Neostigmine acts by inhibiting the enzyme acetylcholinesterase. This enzyme is involved in degradation of ACh, consequently neostigmine increases the synaptic level of ACh. Muscle weakness can be improved by stimulation of NM receptors at muscle end plate due to increased ACh.