Drugs affecting muscle spasm and spasticity

• Drugs used to manage muscle spasm and spasticity are divided into muscle relaxants and spasmolytics. Muscle spasm is a sudden, violent, involuntary contraction of a muscle or group of muscles. • Cyclobenzaprine (Flexeril) is the prototype for centrally acting muscle relaxants. • Centrally acting muscle relaxants do not act directly on painful muscles; rather, they work by their CNS depressant activity. • Most centrally acting muscle relaxants are not effective in treating spasticity. • In addition to their CNS depressant effects, centrally acting muscle relaxants have anticholinergic and antihistaminic effects. • Safety is a primary concern for patients receiving centrally acting muscle relaxants and spasmolytics. • Centrally acting muscle relaxants should be given with caution to older adults. They are not indicated for use in children. • Spasticity is a prolonged increased tone in muscles that may lead to contraction. • Baclofen (Lioresal) is the prototype centrally acting spasmolytic drug. • Gabapentin (Neurontin) is a miscellaneous antiepileptic drug that also has spasmolytic properties. • Dantrolene (Dantrium) is a peripherally acting spasmolytic that affects spasticity within the muscle fi bers. • Botulinum toxin type A (Botox) is used to manage chronic muscle spasms that do not respond to other treatment methods. It may also be used for cosmetic purposes. • Spasmolytics should be used cautiously in patients who require spasticity to remain upright.