What is a Muscle Relaxer?
A muscle relaxer is a type of medicine usually prescribed as a pain medication. Also known as skeletal muscle relaxants (SMRs), muscle relaxers are commonly referred to as simply pain pills. While a muscle relaxer doesn’t contribute in any way to facilitate healing at the site of an injury, it does promote the relief of pain associated with the injury. This is achieved by decreasing the mobility and contraction of skeletal muscle.
A muscle relaxer generally falls into two classifications: A neuromuscular blocker or a spasmolytic. As the name of the former implies, neurotransmission activity to the muscle is blocked by either inhibiting acetylcholine synthesis or its action at receptor sites. In effect, this type of muscle relaxer causes temporary paralysis of the muscles. For this reason, this kind of muscle relaxer is sometimes given just prior to surgical procedures as an alternative or supplemental anesthesia.
A spasmolytic muscle relaxer, on the other hand, is often referred to as a centrally-acting muscle relaxer due to its impact on the central nervous system. As the name spasmolytic suggests, this type of muscle relaxer targets muscles with the purpose of inhibiting spasms, in addition to alleviating pain. This is the most commonly prescribed type of muscle relaxer. In fact, the very term muscle relaxer generally refers to a spasmolytic, although its reach of definition has been extended to include neuromuscular blockers as well. However, since some pain medications in this class do not exhibit central nervous system activity, a more accurate term for a spasmolytic is simply antispasmodic.
While many patients may respond positively to a muscle relaxer in terms of pain relief, variations between different drugs in this class make some medications less appropriate for certain injuries or conditions. For instance, baclofen is a muscle relaxer that has been found to be helpful in some neurological conditions, such as multiple sclerosis or cerebral palsy. However, this specific muscle relaxer is not recommended for orthopedic disorders.
Taking a muscle relaxer for any condition does present certain risks. For one thing, one or more side effects may occur, such as blurred vision, dizziness or drowsiness. For another, some muscle relaxers may intensify the effects of other medications, further suppressing the central nervous system. In addition, there is the risk of dependency and abuse with long-term use of these pain medications overall.
There are also certain circumstances in which the use of some types of muscle relaxer is contraindicated. For example, metaxalone may cause false serum glucose readings in diabetics. Another muscle relaxer, methocarbamol, may increase the risk of seizures in epileptics.
Since any type of muscle relaxer can carry specific risks to certain individuals, it is important that the patient discuss their medical condition and history at length with their physician. In addition, the patient should fully disclose all other medications currently being taken, including over-the-counter drugs and dietary supplements.
Written by Karyn Maier
