– Pharmacology of Muscle Relaxants and Their Antagonists

In 1942 Griffith and Johnson suggested that d-tubocurarine (dTc) is a safe drug to use during surgery to provide skeletal muscle relaxation. One year later, Cullen described its use in 131 patients who had received general anesthesia for their surgery. In 1954, Beecher and Todd reported a sixfold increase in mortality in patients receiving dTc versus those who had not received a relaxant. The increased mortality was due to a general lack of understanding of the pharmacology of neuromuscular blockers and their antagonism. The impact of residual neuromuscular blockade postoperatively was not appreciated, guidelines for monitoring muscle strength had not been established, and the importance of pharmacologically antagonizing residual blockade was not understood. Since then, the understanding of neuromuscular blocker pharmacology has improved, and relaxants have become an important component of many anesthetics and have facilitated the growth of surgery into new areas with the use of innovative techniques.