T48.1X4 - Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], undetermined T48.1 - Poisoning by, adverse effect of and underdosing of skeletal muscle relaxants [neuromuscular blocking agents] T48.1X - Poisoning by, adverse effect of and underdosing of skeletal muscle relaxants [neuromuscular blocking agents] T48.1X4 - Poisoning by skeletal muscle relaxants [neuromuscular blocking agents], undetermined