Muscle relaxants: Uses, common brands, and safety info

If you’ve ever experienced a muscle spasm, you may have taken a skeletal muscle relaxant like Skelaxin or Flexeril for pain relief. Muscle pain or spasms can range from mild cramps or twitches to debilitating pain, where you feel like you can’t even move. 

Rest, ice or heat, physical therapy, and a nonsteroidal anti-inflammatory drug (NSAID) like ibuprofen are popular first-line treatments for musculoskeletal pain. However, if NSAIDs are not enough or if your pain is very severe, your healthcare provider may prescribe a prescription-strength muscle relaxant for acute pain. 

There are many FDA-approved muscle relaxants available as treatment options. Continue reading on to learn all about muscle relaxants. The tablet below lists the most common muscle relaxants.

What are muscle relaxants?

Muscle relaxants treat muscle spasms. Your healthcare provider may prescribe a muscle relaxant along with suggesting other measures like rest, physical therapy, and ice or heat, to help you heal from an acute injury. Some healthcare providers only prescribe a muscle relaxant if an NSAID does not adequately alleviate the pain. 

A muscle relaxant for an injury or acute pain should only be used for two to three weeks at the most. Some muscle relaxants are used to treat chronic conditions like multiple sclerosis and can be taken for a longer time under the supervision of a healthcare professional.

How do muscle relaxants work?

Antispasmodic muscle relaxants like Soma or Robaxin for acute injury do not work on the muscle itself. They work on the central nervous system (CNS) and cause CNS depression. CNS depression causes sedation and muscle-relaxing activity.

The antispastic muscle relaxant dantrolene does not work on the CNS directly. Dantrolene works on the skeletal muscle, affecting the contractile response, causing relaxation. Baclofen is also an antispastic muscle relaxant. The way that baclofen works is not entirely understood, but it is thought to cause CNS depression. 

Valium is a benzodiazepine. Although it is usually used for anxiety, it is sometimes prescribed for its muscle-relaxant effects. Valium works on a neurotransmitter called GABA, or gamma-aminobutyric acid, causing its relaxing effects. 

What are muscle relaxants used for?

Indications depend on the specific drug. Examples include:

• Acute, painful musculoskeletal injury

• Back pain or low back pain

• Neck pain

• Pinched nerve

• Fibromyalgia

• Multiple sclerosis

• Cerebral palsy

• Spinal cord injury

• Stiff person syndrome

• Paraplegia

Muscle relaxants are most commonly used to relieve muscle spasms from an acute, painful injury. These medications should be used for short-term use. They should also be used along with rest, physical therapy, and ice or heat—your healthcare professional can give medical advice on these other measures. 

Some muscle relaxants are used for their muscle-relaxing activity, but they are not used for your typical acute muscle injury. For example, Lioresal (baclofen) is a muscle relaxant and antispastic. It treats spasms (spasticity) related to multiple sclerosis, and sometimes due to spinal cord diseases or conditions. Dantrium (dantrolene) also treats spasticity from conditions like multiple sclerosis, spinal cord injury, strokes, or cerebral palsy.

Types of muscle relaxants

Antispasmodics (for acute musculoskeletal conditions)

Antispasmodics are traditionally used for acute, painful musculoskeletal injuries. For example, if you “throw out” your back and can’t move, an antispasmodic may be appropriate, if an NSAID is not adequate. Some examples of antispasmodics are Flexeril, Robaxin, Soma, and Norflex. 

Antispastics

Antispastics, such as Lioresal and Dantrium, are not used for acute muscle injury. They can treat spasms from conditions like multiple sclerosis or spinal cord injury. Dantrium also treats strokes and cerebral palsy. 

Benzodiazepines

Valium (diazepam) is a benzodiazepine that treats anxiety. However, it can also help relax muscles. Valium can treat muscle spasms due to muscle injury as well as upper motor neuron disorders such as cerebral palsy.

Who can take muscle relaxants?

Men

Generally, adult men can take muscle relaxants unless they fall under one of the restrictions below. 

Women

Generally, adult women can take muscle relaxants unless they are pregnant or fall under one of the other restrictions below. 

Children

Because most muscle relaxants have not been studied in children, they are generally not prescribed to pediatric patients. Dantrolene may be used in pediatric patients for certain chronic conditions that cause spasticity, such as spinal cord injury, cerebral palsy, or multiple sclerosis. 

Seniors

Older adults should generally not take muscle relaxants because of the side effects and risks associated with them. Muscle relaxants are listed on the Beers List of potentially inappropriate medications for older adults. The Beers List guidelines state that older adults poorly tolerate most muscle relaxants due to the side effects, sedation, and increased risk of fractures.

Are muscle relaxants safe?

Muscle relaxant recalls

• Robaxin recall, May 2019

• Cyclobenzaprine recall, February 2018

Muscle relaxants restrictions

Tell your doctor about all of the medical conditions you have. Some muscle relaxants are associated with liver problems. If you have liver or kidney/urinary problems or glaucoma, this could affect whether a muscle relaxant is safe for you to take, depending on the particular medication. 

Besides the general restrictions listed above, consult your healthcare provider for individual advice on the safety of a muscle relaxant, because everyone has different symptoms and a unique medical history that can affect which medication is safest and most appropriate for you. 

Drug-drug interactions

Muscle relaxants have various drug interactions. Combining muscle relaxants with certain medications, such as SSRI, SNRI, or other antidepressants, opioid pain medications, cough suppressants, migraine triptan drugs, among others, can cause a potentially life-threatening condition called serotonin syndrome. 

Valium has a black box warning, which is the strongest warning required by the FDA in the United States. Do not take Valium with an opioid. The combination of a benzodiazepine, like Valium with opioid pain medication, can cause profound sedation, slowed breathing, coma, and death. 

Tell your healthcare provider about all the medications you take, including prescription, OTC, and vitamins, so he or she can determine if a muscle relaxant is safe with the other medications you take.

Muscle relaxers and alcohol

Do not drink alcohol while taking a muscle relaxant. Alcohol and other CNS depressants can cause additive effects when combined with a muscle relaxant.

Other warnings:

• Do not drive or operate machinery while taking a muscle relaxant. 

• Ask your doctor or pharmacist if you should take your muscle relaxant with food or on an empty stomach.

• If you are taking a muscle relaxant and have symptoms of an allergic reaction, such as hives, difficulty breathing, or swelling of the lips, tongue, or throat, seek emergency medical treatment.

• When discontinuing a muscle relaxant, ask your healthcare provider if you should taper it slowly. Some muscle relaxants can lead to withdrawal symptoms if stopped abruptly. 

Can you take muscle relaxants while pregnant or breastfeeding?

Generally, muscle relaxants are not prescribed to women who are pregnant. There are not enough studies to establish safety in this population. Therefore, muscle relaxants should only be prescribed if the healthcare provider determines benefits outweigh risks. Muscle relaxants are generally not used in breastfeeding mothers. Consult your healthcare provider for medical advice if you are pregnant, plan to become pregnant, or breastfeeding.

Are muscle relaxants controlled substances?

Soma and Valium are controlled substances. This means they have a potential for abuse and dependence. Avoid these medications if you have a history of a substance use disorder. The other muscle relaxants are not controlled substances.

Common muscle relaxants side effects

Specific side effects can vary by the drug and dosage. The most common side effects of muscle relaxants include:

• Drowsiness or fatigue 

• Dizziness

• Weakness 

• Headache 

• Dry mouth

• GI (gastrointestinal) problems like abdominal pain, nausea, vomiting, constipation, diarrhea

• Confusion

• Nervousness

• Agitation 

• Tremor 

• Impaired coordination

• Irritability 

• Tachycardia (fast heartbeat)

• Insomnia 

• Urinary problems 

This is not a full list of possible side effects. Other side effects may occur. Ask your doctor what side effects you should expect and how to address them.

How much do muscle relaxants cost?

Muscle relaxants have a wide price range from about $25 (generic Valium) to $226 (generic Skelaxin), depending on the specific drug, quantity, and dosage. Since muscle relaxants are available in generic form, you can expect to pay much less than if you were paying for the brand-name counterpart. 

Insurance plans cover most generic muscle relaxants, and Medicare prescription plans vary. Check with your specific plan for coverage details.

You can always use a free SingleCare card to save money on your muscle relaxant prescriptions at any participating pharmacy. Some muscle relaxers cost only $4 with a free SingleCare coupon.