Are Muscle Relaxers Addictive? Risks and Precautions

What you will learn

• Muscle relaxers are prescription medications for people with muscle spasticity, spasms, or tension.
• Different types of muscle relaxers have different ways of affecting the muscles for different conditions.
• Muscle relaxers have risks, including possible misuse, abuse, or addiction.

Muscle relaxers are prescription medications for muscle spasms, spasticity, and tension caused by conditions like multiple sclerosis (MS). They’re only intended for short-term use, however, because of their addiction potential.

What Are Muscle Relaxers?

Muscle relaxers, also known as muscle relaxants, are prescription medications that affect muscle function to treat symptoms like muscle spasms, muscle spasticity, and musculoskeletal tension and pain.

There are two major drug classes for muscle relaxers: antispastics and antispasmodics. These two classes are used differently and have different side effects and mechanisms of action. Skeletal muscle relaxants, also known as antispastics, work on the muscles that cause movement, so they’re used to treat muscle tension and spasticity.[1] Smooth muscle relaxants, also known as antispasmodic relaxants, work on the smooth muscles, such as the stomach, intestines, and blood vessels, which operate outside your conscious control.[2]

A key distinction between antispastics and antispasmodics, both considered muscle relaxers, is that antispastics work on skeletal muscles involved in voluntary movement. In contrast, antispasmodics can affect both skeletal and smooth muscles depending on the specific medication.

The commonly used antispasmodic muscle relaxants include:[3]

• Cyclobenzaprine, sold as Fexmid and Flexeril
• Carisoprodol, sold as Soma and Vanadom
• Chlorzoxazone, sold as Lorzone, Parafon Forte DSC, and Relax-DS
• Metaxalone, sold as Metaxall and Skelaxin
• Methocarbamol, sold as Robaxin
• Orphenadrine, sold as Norflex

Antispastic skeletal muscle relaxants like Lioresal (baclofen) and Dantrium (dantrolene). Two skeletal muscle relaxers have antispastic and antispasmodic effects: Valium (diazepam) and Zanaflex (lizanidine).

What Do Muscle Relaxants Treat?

Antispastics and antispasmodics have different uses. Antispastic muscle relaxers treat muscle spasticity, disrupting muscle movement patterns that can cause muscles to contract simultaneously. This can be caused by damage to the nerve pathways in the brain or spinal cord, which can occur with MS, cerebral palsy, spinal cord injuries, brain or head injury, stroke, and Lou Gehrig’s disease: amyotrophic lateral sclerosis (ALS).

Antispasmodic skeletal muscle relaxants treat musculoskeletal and myofascial pain, common in the back, and muscle spasms. However, these medications are often used if other medications are ineffective because of their risks and side effects.

How Do Muscle Relaxers Work?

There are multiple drug classes for skeletal muscle relaxers, but many are central nervous system (CNS) depressants and cause a sedative effect. This prevents the nerves from sending pain signals to the brain.

Antispastic medications work on the spinal cord or skeletal muscles directly to relieve involuntary spasms or tightness, compared to antispasmodics that decrease muscle spasms by affecting the CNS.[4]

Muscle Relaxer Side Effects

Prescription muscle relaxers can have a wide range of side effects based on their specific drug class, but many have similar side effects because of their effects on the brain:[5]

• Drowsiness
• Dizziness
• Nausea
• Headache
• Dry mouth

What are the Risks of Muscle Relaxers?

Severe drowsiness caused by muscle relaxers can have serious risks, such as injuries or death. It’s important to avoid any activities that require alertness until you know how the drug affects you.

Muscle relaxers should never be combined with alcohol or other depressant drugs. Doing so can depress the central nervous system and cause dangerous levels of sedation, as well as compounding side effects like dizziness and mental status change.[6] There’s an increased risk of overdose or liver damage as well.

Some muscle relaxers have serious side effects, such as allergic reactions and serotonin syndrome, a dangerous condition that involves serotonin levels that have built up in the brain and cause tremors, confusion, and sweating.

Muscle Relaxer Overdose

Muscle relaxers can be misused or abused, particularly drugs like carisoprodol and diazepam. These drugs are intended for short-term use, so if you take them for long periods or at high doses, you can build a tolerance and physical dependence that can develop into an addiction.

Most muscle relaxers have a sedative effect, so they can be misused or abused with other substances to enhance dissociation, euphoria, or relaxation. If you misuse muscle relaxers, you’re at an increased risk of potentially fatal overdose.

The symptoms of a muscle relaxer overdose can vary by the specific drug, but they may include:[7]

• Respiratory depression
• Cardiac arrest
• Hallucinations
• Seizures
• Loss of consciousness
• Coma
• Death

If you suspect someone is overdosing on muscle relaxers, call 911 immediately. Stay with them until emergency services arrive. If they stop breathing, you can administer CPR.

Precautions for Muscle Relaxers

If you’re taking muscle relaxers, it’s important to take some safety precautions to avoid serious risks:

• Avoid driving a car or operating heavy machinery if you experience drowsiness.
• Don’t combine muscle relaxers with alcohol, which can compound the sedative effects and increase the risk of severe drowsiness or overdose.
• Don’t take higher doses or more frequent doses than prescribed.
• Avoid taking muscle relaxers for effects other than what they were prescribed for, such as euphoria.

Are Muscle Relaxers Addictive?

Muscle relaxers vary significantly, but several of them are controlled substances because of their addiction potential. Carisoprodol and diazepam, a benzodiazepine, are among them. These drugs build tolerance and dependence quickly, leading to withdrawal if you stop taking them suddenly.

Some drugs that are considered muscle relaxers are more addictive than others. If you want to stop taking them, you should talk to your doctor about doing so safely. If dependence has developed, you can experience significant and possibly life-threatening withdrawal symptoms.

For some drugs, medical detox is the best first step to address withdrawal. You’ll have a medical team to monitor your health, administer drugs as needed, adjust your taper schedule, and prevent complications while the drug clears your system.

If you have an addiction to muscle relaxers, more extensive treatment may be necessary to address the emotional, social, and psychological aspects of addiction. This may include individual, group, and behavioral therapy as part of an inpatient or outpatient program.

Avoid Misuse and Abuse of Muscle Relaxers

Muscle relaxers include a variety of drugs that have different mechanisms of action, side effects, risks, and addiction potential. However, many muscle relaxers can be addictive, especially if they’re misused, and carry serious risks of withdrawal and overdose.

Amanda is a prolific medical content writer specializing in eating disorders and addiction treatment. She graduated Magna Cum Laude from Purdue University with a B.S. in Social Work. Read more