What are muscle relaxers?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 24, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Muscle relaxers are a diverse group of medications that help reduce muscle spasms and pain by acting on the central nervous system or directly on skeletal muscles, with options including cyclobenzaprine, methocarbamol, and baclofen. For acute muscle spasms, these medications are commonly recommended for short-term use, typically 2-3 weeks, due to their potential for habit-forming and loss of effectiveness over time 1. The most effective muscle relaxants for acute low back pain are those that are moderately superior to placebo for short-term pain relief, with a relative risk of not achieving pain relief of 0.80 (CI, 0.71 to 0.89) at 2 to 4 days 1.

Key Characteristics of Muscle Relaxers

  • They work by either blocking pain signals in the brain or by directly affecting muscle function
  • Most muscle relaxers cause drowsiness, so they should be taken when you don't need to drive or operate machinery
  • Side effects may include dizziness, dry mouth, and blurred vision
  • They are typically used in combination with rest, physical therapy, and over-the-counter pain relievers like ibuprofen or acetaminophen

Recommendations for Use

  • Cyclobenzaprine (Flexeril) 5-10mg three times daily for 2-3 weeks is commonly recommended for acute muscle spasms 1
  • Alternatives include methocarbamol (Robaxin) 1500mg four times daily, or baclofen (Lioresal) 5-10mg three times daily
  • If muscle pain persists beyond a few weeks, consult a healthcare provider as this may indicate a more serious underlying condition requiring different treatment 1

From the FDA Drug Label

Cyclobenzaprine hydrochloride tablets are indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions Baclofen USP, is a muscle relaxant and antispastic, available as 10 mg and 20 mg tablets for oral administration.

Muscle relaxers are a class of drugs that provide relief from muscle spasm and its associated signs and symptoms, such as pain, tenderness, limitation of motion, and restriction in activities of daily living. Examples of muscle relaxers include cyclobenzaprine and baclofen 2, 3.

From the Research

Definition and Types of Muscle Relaxers

  • Muscle relaxers are a group of medications used to treat muscle spasms, pain, and spasticity [ 4 ].
  • They can be classified into two main categories: antispasmodic and antispasticity muscle relaxants [ 4 ].
  • Antispasmodic muscle relaxants include benzodiazepines (e.g., diazepam, alprazolam) and non-benzodiazepines (e.g., cyclobenzaprine, carisoprodol) [ 4 ].
  • Antispasticity muscle relaxants include baclofen and dantrolene [ 4 ].

Uses of Muscle Relaxers

  • Muscle relaxers are used to treat various conditions, including musculoskeletal pain, spasticity, and anxiety [ 5 ].
  • They are often prescribed for acute and chronic pain management [ 6 ].
  • Muscle relaxers can be used to treat sleep disorders, epilepsy, and spasticity due to central nervous system pathology [ 7 ].

Safety and Efficacy of Muscle Relaxers

  • The efficacy and safety of muscle relaxers vary depending on the specific medication and condition being treated [ 4 ].
  • Some muscle relaxers, such as baclofen and tizanidine, have been shown to be effective in treating spasticity [ 5 ].
  • However, muscle relaxers can also have significant adverse effects, including drowsiness, dizziness, and dependence [ 4 , 7 ].
  • The concomitant use of prescription opioids and muscle relaxers can increase the risk of opioid overdose [ 8 ].

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.