Side Effects and Risks of Muscle Relaxers

Muscle relaxers can be helpful in alleviating back pain, but people should be aware of potential side effects and risks.

Side Effects Associated with Muscle Relaxers

Side effects of muscle relaxers include:

• Sleepiness or grogginess
• Fatigue
• Dry mouth
• Constipation
• Nausea

More serious side effects include:

• Light-headedness or fainting
• Blurred vision
• Confusion
• Urinary retention

Any serious side effects should be reported to a doctor immediately.

Risks Associated with Muscle Relaxers

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. Muscle relaxants are generally used for a few days and up to 3 weeks, but are sometimes prescribed for chronic back pain or neck pain.

See Medications for Back Pain and Neck Pain

To minimize risk, the doctor should be informed of any history of seizures, liver disease, and any other medical conditions or concerns. Women should inform their doctors if they are pregnant, plan to become pregnant, or are breast-feeding.

• Sleepiness. Because muscle relaxers are total body relaxants, they typically induce grogginess or sleepiness. As a result, it is not safe to drive or make important decisions while taking muscle relaxers. Muscle relaxers are often suggested for evening use due to their sedative effect.
• Interactions with alcohol. Drinking alcohol can be especially dangerous when taking muscle relaxers. The sedative effect of the medication is intensified with alcohol use, and combining the two can be fatal.

  See Alcohol Avoidance

• Allergic reactions. No medication should be taken if the person has had an allergic reaction to it in the past, even if the reaction seemed mild. Symptoms of an allergic reaction include swelling in the throat or extremities, trouble breathing, hives, and chest tightness.
• Potential for abuse. Muscle relaxers have a risk of misuse and abuse. Some muscle relaxers, such as cyclobenzaprine, can be habit-forming on their own. Others may be taken in conjunction with other drugs, such as opioids, to create a high, and are therefore more likely to be abused.

  See Opioids for Back Pain: Potential for Abuse, Assessment Tools, and Addiction Treatment

• Tapering off. Stopping a muscle relaxer abruptly can be harmful. Instead, the doctor will prescribe a gradual reduction in dosage.

Muscle relaxers are widely prescribed for acute back pain, often in conjunction with an over-the-counter or prescription pain medication. They are generally prescribed for a short time to relieve pain in the lower back or neck caused by muscle spasms, also called muscle cramps.

See Types of Back Pain: Acute Pain, Chronic Pain, and Neuropathic Pain

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.