Methocarbamol is used as an adjunct to rest, physical therapy, analgesics, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. Skeletal muscle relaxants generally appear to be more effective than placebo in providing symptomatic relief of acute low back pain, but are associated with a high incidence of adverse effects. Although comparative studies are limited, available data suggest that various skeletal muscle relaxants generally have similar efficacy for such use. Acute low back pain usually is a benign and self-limiting condition that improves spontaneously over time; if pharmacologic therapy is required, an analgesic agent such as acetaminophen or a nonsteroidal anti-inflammatory agent (NSAIA) generally is recommended as first-line therapy for most patients. Skeletal muscle relaxants (alone or in combination with analgesics) may be used as an option for short-term relief of acute low back pain; however, the possibility of adverse effects, particularly adverse CNS effects, should be considered. In general, skeletal muscle relaxants should be used with caution after weighing the potential risks against the benefits in individual patients.
Well-controlled clinical studies have not conclusively demonstrated whether relief of musculoskeletal pain by methocarbamol results from skeletal muscle relaxant effects, sedative effects, or a placebo effect of the drug. Most authorities attribute the beneficial effects of methocarbamol to its sedative properties. The drug is ineffective in the treatment of skeletal muscle hyperactivity secondary to chronic neurologic disorders, such as cerebral palsy, and other dyskinesias.
Methocarbamol has been used as an adjunct to debridement, tetanus antitoxin, penicillin, tracheotomy, fluid and electrolyte replacement, and supportive therapy in the management of tetanus. However, most authorities prefer administration of diazepam, meprobamate, barbiturates, or chlorpromazine, and in severe cases, administration of neuromuscular blocking agents.
Although some clinicians have used IV or IM methocarbamol to terminate epileptic seizures, the drug may precipitate seizures.
(See Cautions: Adverse Effects.)