The drug that produces neuromuscular blockade by persistent depolarization is:: (A) D-tubocurarine., (B) Gallamine., (C) Pancuronium., (D) Decamethonium.
Answer is D. Decamethonium is a peripherally acting skeletal muscle relaxant. It produces an immediate and rapid depolarization of the motor end plate. D-tubocurarine, pancuronium and gallamine are competitive antagonists of acetylcholine at the motor end plate and produce skeletal muscle relaxation.