I have on- and off-again low back pain. Would a prescription muscle relaxant be a good idea during a flare-up?
It might be, depending on the cause of your back pain and whether you have any contraindications—but these prescription-only drugs should not be used as initial treatment.
Muscle relaxants are used to treat muscle spasms (cramping or twitching of muscles that may occur when muscles, ligaments, tendons, or bones are injured) and related muscle pain. They are often prescribed in particular for low back pain, which is frequently related to back muscle weakness, as weak muscles have a tendency to spasm.
Among the drugs are orphenadrine (brand name Norflex), cyclobenzaprine (Flexeril, Fexmid, Amrix), and tizanidine (Zanaflex). Other muscle relaxants not discussed in this article are prescribed for treating muscle spasticity, which may occur in such conditions as multiple sclerosis and strokes.
Typically, muscle relaxants should be prescribed for acute low back pain only after physical therapy or other treatments have been tried (see advice at end). That’s because they have a lot of side effects and the potential to be misused and lead to dependence. Moreover, if you develop a dependence and stop taking them, you could end up going through withdrawal. If they are prescribed, you should take them only for a short time—usually no more than two to three weeks.
A study published in JAMA Open Network in 2020 noted that prescriptions given at doctor office visits for continuing muscle relaxant use tripled between 2005 and 2016 in the U.S. More concerning, a majority of the patients (almost 70 percent) were also prescribed an opioid, which significantly increases the risk of serious side effects. And a disproportionately high percentage of the patients were older adults, who are more prone to the ill effects of these drugs.
Unfortunately—and curiously—there is no clear-cut evidence that muscle relaxants do a better job of treating muscle spasms and related muscle pain than acetaminophen or NSAIDs. A 2021 review paper in BMJ that evaluated dozens of studies concluded that there is “considerable uncertainty” about whether short-term use of muscle relaxants for low back pain has any clinically significant benefits in terms of pain or function.
If your doctor prescribes a muscle relaxant, there are several things to be aware of. Though side effects vary across the different medications, in general they may cause drowsiness, dizziness, nausea, dry mouth, headache, and fatigue. Their use can increase falls, which is a particular concern among older people. And there can be serious consequences if you overdose on a muscle relaxant, including seizures, cardiac arrest, coma, and even death.
Because muscle relaxants can make you sleepy, you shouldn’t drive or operate machinery when taking them; it’s generally best to take them at bedtime. You shouldn’t drink alcohol when taking them either. After all, muscle relaxants and alcohol are both central nervous system (CNS) depressants, and taking them together increases the risk of side effects including fainting, memory difficulties, drowsiness, and dizziness.
According to the Health in Aging Foundation (established by the American Geriatrics Society), muscle relaxants are “potentially inappropriate” for older people to take. Alternative treatments for low back–related muscle spasms are physical therapy, heating or cooling of the affected area, therapeutic massage, stretching, acetaminophen, and NSAIDs (nonsteroidal anti-inflammatory drugs such as naproxen and ibuprofen, for short-term use only). A physical therapist can treat you and also advise on a home exercise and stretching program. Another possible therapy for muscle spasms is TENS (transcutaneous electrical nerve stimulation).
