Muscle relaxers are a group of drugs that have a sedative effect on the body. They work through the brain, rather than directly on the muscles. Common side effects include drowsiness and constipation. While it is important to take drowsiness into account during the day, the sedation can be helpful at night, when pain might otherwise interfere with sound sleep.
If a medication seems to cause problems, it is important to notify the doctor. Each medication works a little differently, and the doctor may be able to prescribe another that fits the individual’s needs better.
Common Uses for Treating Back Pain
There is some evidence in the medical literature of effectiveness of muscle relaxants when used for acute back or neck pain on a short-term basis (e.g. up to one or two weeks). They can promote recovery by blocking the feeling of pain, so patients can get the rest they need to heal.
Common uses of muscle relaxants for back or neck pain include:
- For muscle spasms
Muscles spasms occur when a muscle—or muscles—tighten up or cramps suddenly. The pain can be severe. When this happens in the back or neck, it is often caused by lifting a heavy object or twisting the body, leading to a strained muscle. Muscle relaxants may be prescribed along with pain relievers to ease the spasms.
- Emergency room care
Checking to see if there is a serious problem is the initial focus of emergency room treatment for back pain. If the situation is not related to a serious underlying issue, such as an unstable fracture or a tumor, the patient may be prescribed muscle relaxers with painkillers for a short time to treat an intensely painful sprain or strain of muscles, ligaments, or tendons.
- Following spine surgery
Muscle spasms are common following surgery, even if the original pain has eased. In some cases, the muscle spasms occur in parts of the body well away from the surgery. Muscle relaxants are often given in the hospital and patients may receive a prescription during the initial days or weeks of recovery at home. The doctor’s directions, and directions on the pill bottle, should be followed closely. It is useful to discuss in advance whether the doctor wants the medication to be taken on a set schedule, to stay ahead of the pain, or to be used as needed. It may be helpful to stagger doses of pain medication and muscle relaxers, rather than take both at the same time, so there is always some medication in the body and the pain does not become too intense as the medication is wearing off.
- During physical therapy
Muscle relaxants may be prescribed while the patient is starting a new physical therapy program. The muscle relaxant may aid in range of motion during physical therapy, may help alleviating anxiety related to starting with physical therapy and exercise, and may aid in pain related to possible pain flare-ups related to muscle spasm.
Muscle relaxants can be helpful in alleviating acute back pain, but patients should be aware of certain potential problems. For example, both carisoprodol and diazepam are classified by the U.S. Drug Enforcement Administration as Schedule IV controlled substances based on their potential for abuse and addiction.
To minimize risk, the doctor should be informed of any history of seizures, liver disease, myasthenia gravis, or epilepsy, and any other medical conditions or concerns. Women should inform their doctors if they are pregnant, plan to become pregnant, or are breast-feeding.
- Potential for abuse
Muscle relaxants are typically prescribed early in a course of back pain, on a short-term basis. One reason for the short time frame is the potential for dependence or abuse. Muscle relaxants should be kept in a place where visitors and children will not find them. It is illegal to share these medications with anyone else.
- Interactions with antihistamines
Combining muscle relaxants and antihistamines should be avoided. The combination has been linked to an increase in emergency room visits for older adults.1
- Interactions with alcohol
Drinking alcohol can be especially dangerous when taking muscle relaxants. The sedative effect of the medication is intensified with alcohol use, and combining the two can be fatal.
Muscle relaxants usually used to treat back pain and other types of pain include:
Muscle tightness and muscle spasms, including those related to spine injuries, are eased with baclofen. The medication may be helpful in treating multiple sclerosis and stabbing nerve pain. It is available as a tablet and can be taken by children as young as 12 years old. Some common side effects could include nausea and vomiting, confusion, drowsiness, headache, or muscle weakness. Baclofen is rated C in the FDA’s A through X pregnancy safety ranking for medications, with A being the safest.
- Chlorzoxazone (Lorzone, Parafon Forte DSC)
Chlorzoxazone is used for the relief of discomfort from acute, painful, musculoskeletal conditions. It should not be used in patients with hypersensitivity to chlorzoxazone and rare liver toxicity has been reported. The doctor should be contacted in case of loss of appetite; nausea, vomiting, or tiredness; stomach pain; dark urine; pale stools; or yellowing of the skin or eyes. Chlorzoxazone is available as a tablet. It has not been rated by the FDA for safety during pregnancy.
- Carisoprodol (Soma)
Carisoprodol relaxes muscles and eases pain and stiffness caused by acute bone and muscle problems, as may be caused by an injury. It can be habit-forming, particularly if used in conjunction with alcohol or other drugs that have a sedative effect. Patients with a history of acute intermittent porphyria or hypersensitivity to carbamate medications such as methocarbamol should avoid carisoprodol. It is taken by mouth in tablet form and is also available in combination with aspirin or aspirin and codeine. It is rated C in the FDA’s pregnancy safety ranking for medications.
- Cyclobenzaprine (e.g. Amrix, Cyclobenzaprine Comfort Pac Fexmid, FlexePax, Flexeril, FusePaq Tabradol, Therabenzaprine-60)
Cyclobenzaprine eases stiffness and pain from muscle cramps, also called spasms. It is not advised for those with an overactive thyroid, heart rhythm problems, heart failure, or those who have had a heart attack recently. It can be used on a longer-term basis and has a chemical structure related to some antidepressant medications, although it is not an antidepressant. Cyclobenzaprine is not specifically approved for use in fibromyalgia, but is sometimes helpful in treating that condition. It is available as a tablet and extended-release capsule. Cyclobenzaprine is rated B by the FDA for safety during pregnancy, making it the safest of the muscle relaxants to use while pregnant.
- Dantrolene (Dantrium)
Dantrolene helps control chronic spasticity, including that related to spinal injuries. It is also used for conditions such as stroke, multiple sclerosis, and cerebral palsy. Dantrolene is taken as a capsule. It can cause liver problems, so the doctor may order regular blood tests to monitor the medication’s impact. Serious side effects are more likely in those with asthma, emphysema, bronchitis, or other lung diseases. It may cause sensitivity to light. Drowsiness is the most common side effect. The FDA has given dantrolene a C rating for safety in pregnancy.