It is estimated that up to 84% of adults have low back pain at some time in their lives. The vast majority of patients seen in primary care (>85%) will have nonspecific low back pain, meaning that the patient has back pain in the absence of a specific underlying condition that can be reliably identified. For most of these individuals, episodes of back pain are self-limited. Patients who continue to have back pain beyond the acute period (four weeks) have subacute back pain (lasting between 4 and 12 weeks), and some may go on to develop chronic back pain (lasting >12 weeks).
This newsletter focuses on the initial treatment of nonspecific acute back pain.
GENERAL APPROACH TO CARE
The goal of care for patients with acute low back pain is short-term symptomatic relief, since most will improve within four weeks.
We typically advise nonpharmacologic treatment with superficial heat. Massage, acupuncture, and chiropractic work (spinal manipulation) are other reasonable options depending upon patient preference and their cost and accessibility. For patients requiring medications, I suggest a nonsteroidal antiinflammatory drug (NSAID) with or without a skeletal muscle relaxant rather than acetaminophen (Tylenol).
I do not advise bed rest for patients with acute low back pain. Patients who are treated with bed rest have more pain and slower recovery than ambulatory patients.
NONPHARMACOLOGIC THERAPIES
Heat — Heat is often applied with the rationale that it may reduce muscle spasm. A 2006 systematic review including six studies of low back pain found moderate evidence that a heat wrap may reduce pain and disability for patients with pain of less than three months’ duration, although the benefit was small and short-lived.
Massage — There is no evidence that massage offers clinical benefits for acute low back pain. However, a randomized trial found that compared with usual care, when massage was chosen by the patient, it was associated with increased patient satisfaction.
Acupuncture — Acupuncture may be a reasonable option for interested patients with access to an acupuncturist. The evidence of benefit in acute low back pain is limited. Randomized trials of acupuncture tend to be small and heterogeneous in methodology, and blinding is difficult. Systematic reviews of acupuncture for acute low back pain have found inconsistent results. Acupuncture is safe with few side effects.
There is more evidence to support the use of acupuncture in chronic low back pain. (See “Acupuncture”, section on ‘Low back pain’.)
Spinal manipulation — Spinal manipulation is a form of manual therapy that involves the movement of a joint near the end of the clinical range of motion; see a chiropractor for this work.
Exercise and physical therapy — Exercise therapy includes both self-care exercises done by the patient and supervised exercises in the context of physical therapy. In general, we do not refer patients with acute low back pain for exercise or physical therapy. However, we selectively refer patients with risk factors for developing chronic low back pain (eg, poor functional or health status, psychiatric comorbidities) who may benefit from immediate education by a physical therapist on how to avoid recurrences, appropriate levels of activity, and exercises to begin after the acute phase. (See ‘Prognosis’ below and “Exercise-based therapy for low back pain”, section on ‘Acute low back pain: No benefit from exercise therapy’.)
Early referral to a physical therapist may benefit patients with acute back pain who are at higher risk of developing chronic back pain, but this is unproven and may relate to education provided rather than exercise and therapy performed. While studies that have assessed such an approach showed improved outcomes for disability and lost work time, the majority of patients in these studies (>80%) had subacute or chronic rather than acute low back pain.
Other — Many other interventions have been suggested for acute low back pain with little or no evidence to support their use; some of those are as follows: Cold, Muscle energy technique, Traction, Lumbar supports, Mattress recommendations, Yoga and Paraspinal injections.
PHARMACOTHERAPY (Medications)
Initial therapy — If pharmacotherapy is used, we suggest a trial of short-term (two to four weeks) treatment of a nonsteroidal antiinflammatory drug (NSAID) — common names include Ibuprofen, Advil, Motrin, Aleve, Naprosyn, Naproxen, Diclofenac, Voltaren.
Nonsteroidal antiinflammatory drugs — I start with NSAID therapy in patients with acute low back pain without contraindications to this therapy. Many NSAID options exist. I generally start with either Ibuprofen (400 to 600 mg four times daily) or Naproxen (250 to 500 mg twice daily). Doses should be decreased as tolerated. Avoid NSAID’s if you cannot tolerate them, have chronic kidney disease or take a blood thinner. NSAIDs may have significant renal, gastrointestinal, and cardiovascular adverse effects and may be contraindicated in some patients. All NSAID toxicities are more common in older patients.
Limited benefit of acetaminophen — Acetaminophen has historically been considered an option for first-line therapy for low back pain. However, evidence of efficacy has been mixed, and a 2016 Cochrane review concluded that there was high-quality evidence that acetaminophen showed no benefit compared with placebo in acute low back pain. There is also evidence that the addition of acetaminophen to short-term NSAID therapy provides no further benefit. Given that acetaminophen has clear risks and questionable benefit, I do not recommend it as either initial or supplemental therapy for the majority of patients with acute low back pain. However, in selected patients for whom there are no safe alternatives and acetaminophen is the least potentially harmful treatment, I believe it reasonable to consider a trial of acetaminophen as initial therapy. I use acetaminophen 650 mg orally every six hours as needed (maximum 3 grams per 24 hours) for most adults, although we would use a lower total daily dose for older adult patients, those with any hepatic impairment, and patients with other factors that predispose to hepatotoxicity.
Second-line therapy — For patients with pain refractory to initial pharmacotherapy, we suggest the addition of a nonbenzodiazepine muscle relaxant. Muscle relaxants are a diverse group of drugs with similar physiologic effects including analgesia and a degree of skeletal muscle relaxation or relief of muscle spasm; they are available via prescription only. They include benzodiazepines, cyclobenzaprine, methocarbamol, carisoprodol, baclofen, chlorzoxazone, metaxalone, orphenadrine, and tizanidine. I generally do not start these medications as initial therapy, as they tend to have sedating side effects that limit patients’ ability to work or drive. Risks of these agents increase with age. Benzodiazepines should not be used because they are not effective in improving pain or functional outcome and there is potential for abuse.
Opioids — I rarely prescribe an opiate for acute low back pain; the risks outweigh the benefits.
In rare instances, I may prescribe systemic glucocorticoids (i.e. – prednisone or Medrol Dose Pak), Antiepileptics (i.e. – Gabapentin or Lyrica), Topical agents (Lidocaine patch or Diclofenac gel) or Herbal therapies.
PROGNOSIS
The prognosis for acute low back pain is excellent; only one-third of patients seek medical care at all. Of those who present for care, 70 to 90% improve within seven weeks.
Recurrences are common, affecting up to 50% of patients within six months and 70% within 12 months. Similar to the initial episode, recurrences have a favorable prognosis.
Some patients with acute low back pain will go on to develop chronic low back pain. Estimates of the percentage of patients who develop chronic back pain vary. In one prospective cohort study of patients with acute back pain seen in primary care, chronic back pain was diagnosed in 20% of patients within two years of their initial visit. However, other studies have suggested only 5 to 10% of patients with acute low back pain go on to develop chronic low back pain.
PREVENTION
Exercise interventions may have some value in preventing recurrences of low back pain. Strength training, core exercises and daily walking are strongly recommended. Good posture, good ergonomics and maintaining optimal weight are recommended.
SUMMARY AND RECOMMENDATIONS
Most patients with acute low back pain improve regardless of specific management. I typically suggest nonpharmacologic therapy with superficial heat. Massage, acupuncture, and spinal manipulation are other reasonable options. There are no data demonstrating the superiority of one modality over another. Bed rest is not advised, and activity modification should be kept to a minimum.
I do not refer most patients with acute low back pain for exercise or physical therapy. However, I selectively refer patients with risk factors for developing chronic low back pain (eg, poor functional or health status, psychiatric comorbidities) who may benefit from immediate physical education by a physical therapist.
For patients who prefer pharmacologic therapy or in whom nonpharmacologic approaches are inadequate, I suggest short-term (two to four weeks) treatment with a nonsteroidal antiinflammatory drug (NSAID) as initial therapy. Acetaminophen is an acceptable alternative option in patients with a contraindication to NSAIDs, although it has limited efficacy.
For patients with pain refractory to initial pharmacotherapy, I suggest the addition of a nonbenzodiazepine muscle relaxant, usually Cyclobenzaprine. In patients who cannot tolerate or have a contraindication to muscle relaxants, combining NSAIDs and acetaminophen is another option.
Evidence to support the use of opioids and tramadol in acute low back pain is limited. I try to avoid prescribing these at all costs.
Patients who do not improve after four weeks of pharmacotherapy should be reassessed. Some patients with acute low back pain will go on to develop chronic low back pain. Predictors of disabling chronic low back pain at one year include maladaptive pain coping behaviors, functional impairment, poor general health status, presence of psychiatric comorbidities, or nonorganic signs. (See ‘Prognosis’ above.)
Exercise interventions may have some value in preventing recurrences of low back pain.
Happy holidays and Merry Christmas from Dr. Guy and Staff!
