Prescription muscle relaxers serve to treat muscle spasms and control spasticity and pain symptoms in various patients. They come in two families: antispasmodics, which target spasms that arise from conditions like multiple sclerosis or amyotrophic lateral sclerosis (ALS), and antispastics, which are aimed at spasticity caused by neurological disorders such as multiple sclerosis.
Understanding the side effects of muscle relaxers is crucial because these medications affect your central nervous system (brain and spinal cord) in ways that can affect your safety and well-being. Many cause sedation and dizziness [1] that impair your ability to drive or operate machinery. Some carry risks of addiction and withdrawal, while others can cause serious complications like liver damage [2] or respiratory depression.
Most muscle relaxers are prescribed for short-term use, typically two to three weeks. Knowing the potential side effects helps you make informed decisions about your treatment and recognize when to seek medical help.
At Discovery Institute in Marlboro, New Jersey, we provide compassionate support for individuals experiencing problems with prescription medications, including muscle relaxers.
Common antispasmodic medications include carisoprodol (Soma), cyclobenzaprine (Flexeril), metaxalone (Skelaxin), and methocarbamol (Robaxin). These work primarily on the central nervous system to reduce muscle spasms associated with acute musculoskeletal conditions.
Antispastic medications include baclofen (Lioresal), dantrolene (Dantrium), and tizanidine (Zanaflex). Baclofen acts on GABA receptors in the spinal cord, while dantrolene works directly on muscle fibers. Some benzodiazepines, particularly diazepam (Valium), are also prescribed as muscle relaxers.
No muscle relaxers are available over the counter in the United States. Healthcare providers typically prescribe these medications only after other treatments like physical therapy and over-the-counter pain relievers have not provided adequate relief.
Awareness of muscle relaxer risks [3] helps protect your safety. The sedation these medications cause can significantly impair your concentration, reaction time, and coordination, making driving and operating machinery dangerous.
Drug interactions present serious concerns. Combining muscle relaxers with alcohol, opioids, benzodiazepines, or other central nervous system depressants intensifies drowsiness and can lead to respiratory depression [3], liver damage, or fatal overdose.
Certain muscle relaxers, particularly carisoprodol and diazepam, are controlled substances with recognized addiction potential. These medications can lead to physical dependence, tolerance, and withdrawal symptoms when stopped abruptly.
Additionally, older adults [4] often experience more severe sedation and confusion. People with liver or kidney disease [2] may not clear these drugs efficiently, leading to dangerous accumulation.
Sedation and Drowsiness: Most muscle relaxers cause drowsiness and fatigue [1] by depressing central nervous system activity. While this helps muscles relax, it also makes you feel tired, sluggish, and less alert throughout the day.
Dizziness and Light-headedness: Dizziness [3] is widespread due to central nervous system depression. You may feel unsteady, experience spinning sensations, or feel faint when standing up quickly, increasing fall risk.
Nausea and Upset Stomach: Many people experience gastrointestinal discomfort, including nausea [3], stomach upset, or changes in appetite. These effects may be more pronounced when first starting the medication.
Headache and Fatigue: Headaches and general tiredness are common complaints that can persist even after your body adjusts to the medication.
Dry Mouth and Constipation: Some muscle relaxers have anticholinergic properties that reduce saliva production and slow intestinal movement, leading to dry mouth [4] and constipation.
Different muscle relaxers produce unique side effects:
Nervous System Effects: Weakness and muscle fatigue (baclofen, tizanidine, orphenadrine), confusion and disorientation [3] (baclofen, cyclobenzaprine), tremor (orphenadrine), risk of seizures (baclofen, particularly with abrupt discontinuation).
Psychiatric Effects: Insomnia (baclofen), nervousness and agitation (cyclobenzaprine, metaxalone, orphenadrine), hallucinations (orphenadrine, especially in older adults), potential for drug abuse or dependency [1] (carisoprodol, diazepam).
Gastrointestinal Effects: Severe diarrhea (dantrolene), acid reflux or unpleasant taste (cyclobenzaprine), significant stomach upset (metaxalone, orphenadrine).
Genitourinary Effects: Urinary frequency or retention (baclofen, orphenadrine), urine discoloration (chlorzoxazone), urinary tract infections (tizanidine).
Other Effects: Blurred vision (cyclobenzaprine, methocarbamol, orphenadrine), increased eye pressure (orphenadrine), low blood pressure (baclofen), increased heart rate (orphenadrine), elevated liver enzymes [5] (tizanidine, chlorzoxazone, dantrolene).
Central Nervous System Depression: Severe CNS depression [3] can become life-threatening, especially in older adults or when combined with alcohol or cannabis. This can cause profound confusion, extreme drowsiness, slowed breathing, and loss of consciousness.
Liver Toxicity: Certain muscle relaxers, particularly chlorzoxazone, dantrolene, and tizanidine, can elevate liver enzymes or cause liver damage [2]. Warning signs include jaundice, dark urine, pale stools, persistent nausea, and upper right abdominal pain. Seek immediate medical attention if these occur.
Respiratory Depression and Overdose: Combining muscle relaxers with other sedatives creates dangerous respiratory depression. Overdose signs include extreme drowsiness, confusion, slow or irregular breathing, blue-tinged lips, and cold, clammy skin. This is a medical emergency requiring immediate 911 assistance.
Withdrawal Symptoms: Abruptly stopping baclofen, diazepam, or carisoprodol can cause withdrawal, including anxiety, muscle spasms, tremors, insomnia, rapid heart rate, and potentially seizures or hallucinations. Always taper gradually with medical supervision.
Age and Metabolism: Older adults process medications more slowly [4] and are more sensitive to drugs affecting the central nervous system, increasing risks of falls, confusion, and prolonged sedation.
Liver and Kidney Function: Impaired organ function slows drug elimination, causing medications to accumulate to dangerous levels and intensifying side effects.
Dosage and Duration: Higher doses increase side effect likelihood and severity. Long-term use raises concerns about tolerance, physical dependence, and potential addiction. The long-term effects of muscle relaxers may include persistent cognitive impairment and difficulty discontinuing the medication.
Underlying Conditions: Cyclobenzaprine should be avoided by people with heart failure, a recent heart attack, or arrhythmias. Orphenadrine can worsen glaucoma. Give your healthcare provider complete medical history information.
Concurrent Medications: Combining muscle relaxers with antidepressants, antihistamines, opioids, benzodiazepines, or sleep aids multiplies sedation and central nervous system effects.
Only use muscle relaxers under medical supervision and follow dosage instructions precisely. Never share prescriptions, as what is safe for one person may be dangerous for another.
Avoid combining muscle relaxers with alcohol, cannabis, sedatives, or opioids. These combinations dramatically enhance central nervous system depression, raising the risk of respiratory failure and death.
Do not drive or operate heavy machinery until you know how the medication affects you. Even if you feel alert, your reaction time and coordination may be impaired.
When stopping a muscle relaxer, especially after several weeks of use, work with your healthcare provider to taper gradually. Sudden discontinuation can trigger withdrawal symptoms and potentially dangerous seizures.
Consider alternative treatments, including physical therapy, stretching, heat or cold therapy, massage, acupuncture, and non-addictive pain relievers like NSAIDs or acetaminophen.
Carisoprodol and diazepam are controlled substances with significant addiction potential. Carisoprodol breaks down to produce meprobamate, a sedative that can create euphoria. Diazepam can cause physical dependence even when used as prescribed.
Red flags of misuse surface when someone takes more than the prescribed amount, uses the medication more often than advised, feels unable to get through the day without it, becomes obsessively fixated on obtaining refills, or takes muscle relaxers just to experience a “high.” A number of individuals even mix muscle relaxers with opioids or alcohol to amplify the intoxicating effect—a practice that’s extremely dangerous.
If you recognize these patterns, please know that help is available. Dependence on prescription medications is a medical condition that responds to treatment.
At Discovery Institute in Marlboro, New Jersey, we understand that prescription medication problems can develop even when following doctor’s orders. Our comprehensive services help individuals struggling with muscle relaxer misuse, dependence, or co-occurring mental health conditions.
Our programs include medically supervised detoxification with safe withdrawal management, residential treatment with intensive therapeutic support, and intensive outpatient programs offering flexible scheduling. We specialize in dual-diagnosis treatment, addressing both substance use and underlying conditions like chronic pain, anxiety, or depression.
Our compassionate team creates a supportive, non-judgmental environment using evidence-based therapies, including cognitive behavioral therapy (a type of talk therapy that focuses on identifying and changing unhelpful thought and behavior patterns), medication management, group counseling, and holistic approaches. We involve families when appropriate, providing education and support.
If you are experiencing concerning side effects, struggling with dependence, or worried about someone you care about, we invite you to reach out for a confidential consultation. Recovery is possible, and you do not have to face this challenge alone.
Grasping the side effects of muscle relaxers gives you the power to handle these drugs safely. Though they can bring quick, short‑term relief they also carry hazards—sedation, the possibility of dependence, risky interactions, and serious problems such as liver toxicity or respiratory depression, a pattern of slow and shallow breathing that can lead to low oxygen or high carbon dioxide in the blood.
Open communication with your healthcare provider is essential. Report concerning side effects, discuss all medications you take, and ask about alternative treatment options. Many people find that physical therapy, exercise, and non-addictive pain management strategies provide effective relief without the risks.
If you are struggling with side effects, concerned about dependence, or finding it difficult to stop using muscle relaxers, please reach out for help. At Discovery Institute, we provide compassionate, evidence-based care for individuals dealing with prescription medication challenges.
Your well-being matters, and safer alternatives exist. Contact Discovery Institute today for a confidential consultation about managing side effects or addressing dependence.
Our compassionate counselors are standing by to answer any questions you may have. After helping thousands of people over the last 50 years, we have the resources to help you and your family and all your individual needs.
The Discovery Institute aims to provide accurate, ethical, clinically sound information regarding addiction and mental health for individuals and their families. All content published by The Discovery Institute is reviewed for accuracy and clarity by qualified individuals and is medically reviewed. We aim to make complicated subjects easy to understand without resorting to fear-based marketing techniques or misleading assurances. Content is regularly reviewed and updated to reflect current best practices, ensuring readers receive reliable, supportive guidance.
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