When you’re locked in a back spasm or have neck muscles that won’t unwind, it can be hard to function.
Medications that act as muscle relaxers are available both over the counter and by prescription, but they have different levels of effectiveness.
In this article, we’ll explore OTC and prescription muscle relaxers.
We’ll also discuss what muscle relaxers are, how they work, and their side effects and precautions.
Lastly we’ll go over when to see a medical provider for care.
Over-the-Counter Muscle Relaxers
While there aren’t any OTC muscle relaxers, some over-the-counter medications may help treat back pain, spasms, and other conditions that muscle relaxers also help.
- Guaifenesin: This expectorant can provide relief for upper back pain and spasms. If you are using guaifenesin (Mucinex) as a muscle relaxer, check with your healthcare provider to ensure that there are no contraindications.
- NSAIDs: Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil) and naproxen (Aleve) are able to reduce pain and address inflammation, so short-term back pain or muscle spasms may respond to these OTC pain relievers. NSAIDs are also available at higher dosages by prescription.
- Acetaminophen: Acetaminophen (Tylenol) works by blocking the body’s ability to make substances that cause pain. In some cases, medical providers may suggest alternating between acetaminophen and NSAIDs since they are different types of drugs.
Prescription Muscle Relaxers
Prescription muscle relaxers are stronger than OTC options but may come with more pronounced side effects.
- Methocarbamol: A muscle relaxer that is available OTC in other countries but not the United States, methocarbamol (Robaxin) treats muscle pain in the back and tends to have fewer sedative effects than other types of muscle relaxers. Studies show that 44% of people who took methocarbamol for up to eight days had muscle pain relief compared to only 18% who did not take it.
- Metaxalone: Metaxalone (Skelaxin) causes the fewest side effects of the muscle relaxers and is less likely to have a sedative effect. It is more expensive than other options, so not all insurance plans cover it.
- Carisoprodol: Carisoprodol (Soma) is a nonbenzodiazepine drug. It is a less commonly used muscle relaxer because it is a Schedule IV substance, in the same class as Xanax, Ativan, and Valium. It should only be used for 2-3 weeks since it can be habit-forming and has not shown to be effective for longer periods of time. It can cause drowsiness and dizzy feelings and is not safe for older adults over age 65.
- Tizanidine: An antispasmodic drug, tizanidine (Zanaflex) is used to address muscle spasticity in people who have cerebral palsy or multiple sclerosis. Tizanidine has fewer side effects than other drugs used for the same purpose. While this medication is effective for chronic muscle spasms, it is not a first choice for back pain or acute muscular problems.
- Baclofen: This muscle relaxant is approved by the U.S. Food and Drug Administration (FDA) for the treatment of multiple sclerosis, spinal cord lesions, clonus, and flexor spasms. It is not typically used for acute back pain but may be prescribed for patients who have back pain from spinal cord injuries. Baclofen (Lioresal) causes drowsiness.
- Cyclobenzaprine: Cyclobenzaprine (Flexeril) is an effective muscle relaxer that causes significant drowsiness. It may also cause dry mouth in older adults. This is often a first-line prescription since it is widely available and is covered by most insurance options as a generic.
What Are Muscle Relaxers?
Muscle relaxers are medications that reduce muscle spasms and muscle pain.
How Do They Work?
There are two types of muscle relaxers:
- Antispasmodics block the transmission of certain neurons in the brain. They reduce spasms and spasticity by directly affecting the central nervous system. These are more commonly prescribed for acute back pain such as throwing your back out or having a muscle-related injury.
- Antispastics have a direct effect on the spinal cord or skeletal muscles. They relax tight muscles and calm spasms. These are not commonly used for acute back pain but are prescribed to treat chronic conditions that involve dysfunction in the central nervous system or spinal cord. Antispastic drugs are frequently prescribed for multiple sclerosis, cerebral palsy, and spinal cord injuries.
While both types of drugs can relax muscles and may ease pain caused by tight or spasming muscles, they are used for different purposes and have different side effects.
The common side effects of antispasmodic drugs include:
- Blurred vision
- Dry eyes
- Dry mouth
Typical side effects of antispastic drugs are:
- Problems falling asleep or staying asleep
Risks and Precautions
Use caution when taking medications for muscle spasms or back pain.
Many can cause drowsiness or dizziness, increasing the risk for falls or other injuries.
Muscle relaxers should not be paired with alcohol or other medications that can lead to drowsiness such as antihistamines or sedatives.
Pregnant and breastfeeding people should check with their healthcare provider and pharmacist before consuming muscle relaxers.
Older adults and people who have kidney or liver problems may experience more side effects from muscle relaxers.
Tell your medical provider what other medications, OTC drugs, dietary supplements, or herbs that you take to avoid interactions and side effects.
When to See a Medical Provider
If you experience a sudden onset of muscle spasms or severe pain, or if you suspect that you have a chronic problem with muscle spasms, see a medical provider.
Also seek medical care if you have back pain or other muscle spasms that do not resolve.
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Frequently Asked Questions
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Efficacy and safety of guaifenesin for upper back, neck, and shoulder pain: a Phase II proof-of-concept, multicenter, placebo-controlled, repeat-dose, parallel-group study. (2017).
Nonsteroidal anti-inflammatory drugs (NSAIDs). (2022).
Methocarbamol in acute low back pain. A randomized double-blind controlled study. (2015).
Medicines for back pain. (2022).
Considerations for the Appropriate Use of Skeletal Muscle Relaxants for the Management Of Acute Low Back Pain. (2014).