7.10: Skeletal Muscle Relaxants: Therapeutic Uses
Skeletal muscle relaxants are used to relax muscle tone and alleviate painful muscle contractions. However, the choice of skeletal muscle relaxants depends on the duration of the surgical procedure in order to minimize potential side effects. Skeletal muscle relaxants like neuromuscular blocking agents [NMBAs] are commonly employed as adjuvants alongside general anesthetics in clinical settings. NMBAs are also used to maintain controlled ventilation during surgery of the larynx or pharynx as well as emergency endotracheal intubation. By reducing reflex muscle contractions of the organs, they enhance the safety of surgical procedures. NMBAs additionally offer the advantage of reducing epileptic seizures and convulsions, which are often associated with the administration of local anesthetics.
In contrast, spasmolytics are skeletal muscle relaxants that primarily relieve spastic conditions such as cerebral palsy or multiple sclerosis. Centrally acting spasmolytics, including baclofen, diazepam, and tizanidine, act on the central nervous system [CNS] to provide relief from spasms. Others, like dantrolene and botulinum toxin, directly target skeletal muscle cells to reduce muscle spasms. Dantrolene is primarily useful in treating malignant hyperthermia, a potentially fatal genetic condition often triggered in susceptible patients after general anesthesia or following treatment with NMBAs such as succinylcholine. Conversely, botulinum toxin injections are routinely employed in cosmetic therapy to diminish wrinkles
