TREATMENT FOR LOW BACK PAIN
Anti-inflammatory Medication (NSAIDS) For Low Back Pain
Chiropractic For Low Back Pain
Electrical Stimulation For Low Back Pain
Hot and Cold Packs For Low Back Pain
Injectable Medication For Low Back Pain
Muscle Relaxant For Low Back Pain
Muscle Relaxant for Low Back Pain

Overview
Research shows that muscle relaxants are better than placebo, but not more effective than NSAIDS (anti-inflammatory medications) for patients with acute low back pain. Studies comparing how well one muscle relaxant works versus another have generally only been of fair quality.
Most guidelines suggest muscle relaxants work best in the first few days, and should not be used for more than 2-3 weeks.
RESCU Treatment Ratings
R = Risk E = Effectiveness S = Self-Care
C = Cost U = Usefulness (overall rating)
1 = Least Favorable 5 = Most Favorable
RISK: 3/5
Common side effects include sedation, weakness or fatigue, dizziness, and dry mouth. Less common risks include confusion, lethargy, and “anticholinergic” side effects., Some are toxic in overdose and when combined with other substances. Carisoprodol (Soma) is felt to have the highest risk of dependence and abuse, and for that reason some researchers have called for it to be classified as a controlled substance.
Researchers cannot yet determine if one type of muscle relaxant is “safer” than another, though some studies have indicated a higher risk for abuse and addiction with carisoprodol, and tizanidine and chlorzoxazone have been associated with usually-reversible liver toxicity in studies.
Most have side effects which include varying degrees of drowsiness, though some less than others. Carisoprodol is considered a Class IV drug by some states due to its potential for dependence and withdrawal potential. Other drugs such as cyclobenzaprine should be used with caution in patients with heart disease.
Sources:
From Choosing a Skeletal Muscle Relaxant: SHARON SEE, PharmD, BCPS, and REGINA GINZBURG, PharmD, St. John’s University College of Pharmacy and Allied Health Professions, Jamaica, New York
Am Fam Physician. 2008 Aug 1;78(3):365-370. http://www.aafp.org/afp/2008/0801/p365.html
Chou 2005 Drug Class Review on skeletal muscle relaxants