A. Nondepolarizing (competitive) blockers

Although tubocurarine is considered to be the prototype agent in this class, it has been largely replaced by other agents because of its adverse side effects. The neuromuscular-blocking agents have significantly increased the safety of anesthesia, because less anesthetic is required to produce muscle relaxation, allowing patients to recover quickly and completely after surgery. [Note: Higher doses of anesthesia may produce respiratory paralysis and cardiac depression, increasing recovery time after surgery.] Neuromuscular blockers should not be used to substitute for inadequate depth of anesthesia.