Non sedating muscle
At this time, guidelines do not recommend chronic use of muscle relaxants for musculoskeletal pain.
Antispasmodic Agents Agents that fall into this category act at the spinal cord or supraspinal level.
As mentioned previously, there is little data supporting the effectiveness of this agent for musculoskeletal pain and spasm.
As with all central nervous system (CNS) depressants, it must be used with caution in patients taking other CNS depressants, such as opioids.
This is also the mechanism of its adverse effects, including sedation, urinary retention, dry mouth, and constipation.
It is contraindicated in patients with glaucoma, gastrointestinal obstruction, and cardiac spasm.
Most of its drug interactions are pharmacodynamic in nature.
However, because it is metabolized to meprobamate, a sedative/hypnotic similar to barbiturates, there is concern about misuse and abuse.
In fact, The Substance Abuse and Mental Health Services Administration has reported that the number of emergency room visits involving misuse or abuse doubled from 2004 to 2009, more so in patients over the age of 50 years and those using other CNS depressants.
Due to its lack of efficacy and potential for abuse, many institutions do not have it available on their formularies.
The skeletal muscle relaxants are a diverse class of drugs that are used for treating painful muscle spasticity or spasms, which can substantially affect a patient’s ability to function (Table 1).
About 2 million people annually report using muscle relaxants, with about 15% being elderly.Well-controlled clinical studies have not conclusively demonstrated whether relief of musculoskeletal pain by cyclobenzaprine, carisoprodol, chlorzoxazone, metaxalone, or methocarbamol results from skeletal muscle relaxant effects, sedative effects, or a placebo effect of the drug.