<prompt> A patient complains of muscle weakness. It was reversed on administration of neostigmine,because ?It blocks action of acetylcholineIt interferes with the action of amine oxidaseIt interferes with the action of carbonic anhydraseIt interferes with the action of acetylcholine esterase  <response>: Ans. is d i.e., It interferes with the action of acetyl cholinesterase o 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 receptor at muscle end plate due to increased ACh. 