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Skeletal muscle relaxants

Medically reviewed by C. Fookes, BPharm. Last updated on March 20, 2018.

What are Skeletal muscle relaxants?

Skeletal muscle relaxants are drugs that are used to relax and reduce tension in muscles. They are more simply referred to as muscle relaxants.

Some work in the brain or spinal cord to block or dampen down excessively stimulated nerve pathways. These are called centrally acting muscle relaxants and examples include baclofen, methocarbamol, and tizanidine.

Others act directly on muscle fibers and are classified as peripherally acting muscle relaxants. Examples include dantrolene and the different types of botulinum toxin. Although dantrolene acts directly on the muscle itself, it also appears to indirectly act on the central nervous system and can cause drowsiness.

Cannabis extract also has muscle relaxing properties and is thought to act both centrally and peripherally.

What are skeletal muscle relaxants used for?

Skeletal muscle relaxants are mainly used to treat:

What are the differences between skeletal muscle relaxants?

Skeletal muscle relaxants differ in the way they work (centrally or peripherally as discussed above), their side effects, and their effectiveness for certain conditions.

Note that several other medicines, notably diazepam, may also be used as a muscle relaxant and are not listed below.

Are skeletal muscle relaxants safe?

Evidence supporting the effectiveness of skeletal muscle relaxants for muscle spasm is sparse; most trials are old and not of good quality. Skeletal muscle relaxants consist of a varied range of medicines and some may not be suitable for people with certain medical conditions such as an enlarged prostate, epilepsy, glaucoma, intestinal problems, liver or kidney disease, or myasthenia gravis. Many also interact with other medications.

Some, like dantrolene, can adversely affect the liver and blood samples should be taken before treatment to check for any pre-existing liver disease or to establish how well the liver is functioning before treatment, and what effect the drug subsequently has.

Muscle relaxants can affect overall muscle tone and may be dangerous if muscle tone is needed for safe balance or movement. Alcohol can enhance these effects. Many muscle relaxants need to be tapered off slowly, rather than abruptly stopped.

What are the side effects of skeletal muscle relaxants?

Drowsiness is common, particularly with centrally acting muscle relaxants; however, drowsiness can occur with some peripherally acting muscle relaxants, such as dantrolene, as well. This may impair the ability of a person to drive or operate machinery or perform hazardous tasks.

Some may also cause side effects such as a dry mouth, fast heartbeat, gastrointestinal upset (such as nausea, vomiting, constipation), headache, insomnia, light headedness, problems with urination, and other unwanted effects.

Products containing botulinum toxin may cause generalized muscle weakness, vision changes, breathing difficulties and other serious side effects if the toxin spreads from the area of injection.

List of Skeletal muscle relaxants:

View by  Brand | Generic
Drug Name Avg. Rating Reviews
Botox (Pro)
Generic name: onabotulinumtoxinA
5.6
430 reviews
Flexeril (Pro)
Generic name: cyclobenzaprine
6.2
221 reviews
Soma (Pro)
Generic name: carisoprodol
8.9
194 reviews
Zanaflex (Pro)
Generic name: tizanidine
7.6
109 reviews
Skelaxin (Pro)
Generic name: metaxalone
7.1
85 reviews
Robaxin (Pro)
Generic name: methocarbamol
6.3
77 reviews
Amrix (Pro)
Generic name: cyclobenzaprine
7.3
48 reviews
Robaxin-750
Generic name: methocarbamol
5.7
41 reviews
Norflex (Pro)
Generic name: orphenadrine
6.3
30 reviews
Lioresal (Pro)
Generic name: baclofen
7.0
22 reviews
Lorzone (Pro)
Generic name: chlorzoxazone
6.2
21 reviews
Botox Cosmetic (Pro)
Generic name: onabotulinumtoxinA
4.8
12 reviews
Dysport (Pro)
Generic name: abobotulinumtoxinA
6.1
7 reviews
Gablofen (Pro)
Generic name: baclofen
5.0
4 reviews
Fexmid (Pro)
Generic name: cyclobenzaprine
5.8
4 reviews
Xeomin (Pro)
Generic name: incobotulinumtoxinA
5.7
3 reviews
Parafon Forte DSC (Pro)
Generic name: chlorzoxazone
5.9
3 reviews
Myobloc (Pro)
Generic name: rimabotulinumtoxinB
7.2
3 reviews
Lioresal Intrathecal
Generic name: baclofen
5.2
3 reviews
Dantrium (Pro)
Generic name: dantrolene
5.5
3 reviews
Vanadom
Generic name: carisoprodol
5.0
2 reviews
Antiflex
Generic name: orphenadrine
10
1 review
Ryanodex (Pro)
Generic name: dantrolene
No reviews
Revonto (Pro)
Generic name: dantrolene
No reviews
Remular-S
Generic name: chlorzoxazone
No reviews
Paraflex
Generic name: chlorzoxazone
No reviews
Ozobax (Pro)
Generic name: baclofen
No reviews
Orphenate
Generic name: orphenadrine
No reviews
Orfro
Generic name: orphenadrine
3.0
No reviews
Mio-Rel
Generic name: orphenadrine
No reviews
Lyvispah (Pro)
Generic name: baclofen
No reviews
Kemstro
Generic name: baclofen
2.0
No reviews
Jeuveau (Pro)
Generic name: prabotulinumtoxinA
No reviews
Fleqsuvy (Pro)
Generic name: baclofen
No reviews
Dantrium Intravenous (Pro)
Generic name: dantrolene
No reviews
For ratings, users were asked how effective they found the medicine while considering positive/adverse effects and ease of use (1 = not effective, 10 = most effective).

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.