Drug therapy for back pain. Which drugs help which patients?

STUDY DESIGN: A brief review of current literature and issues on drug therapy for low back pain.

OBJECTIVES: To identify current knowledge and future research needs related to drug therapy.

SUMMARY OF BACKGROUND DATA: Drug therapy is one of many possible treatment choices for symptom relief in patients with low back pain. The variety of drugs used suggests that there is no uniquely successful form of drug therapy. One reason for uncertainty and slow progress in this area is the limited quality of many clinical trials for back pain, with inadequate description of patients and outcomes being common deficits.

METHODS: A selective review of randomized trials and systematic literature syntheses on drug therapy is given.

RESULTS: Despite limitations, there is good evidence to support the efficacy of nonsteroidal anti-inflammatory drugs for acute low back pain and fair evidence for the use of muscle relaxants. There is greater controversy about the use of corticosteroids, which have been administered orally, intramuscularly, and epidurally. There is conflicting evidence regarding epidural injection of corticosteroids, but one meta-analysis suggests they may provide a small symptomatic improvement for patients with radiculopathy. Trials of systemic steroids and antidepressant drugs for managing chronic pain are inconclusive. The only randomized trial of local anesthetic injection into trigger points suggested that this treatment was equivalent to that of saline injection, needling without injection, or vapo-coolant spray alone.

CONCLUSION: It seems reasonable to recommend acetaminophen or nonsteroidal anti-inflammatory drugs for patients with acute back pain, with efforts to minimize costs and complications. Muscle relaxants and narcotic analgesics may be appropriate for some patients, but selection criteria are unclear, and these drugs should be prescribed for fixed periods. Drug treatment for chronic low back pain is less clear, and a current controversy centers on the use of chronic narcotic analgesics for such patients. Future research should include evaluating combinations of medications, combinations of medication and physical therapy, systemic corticosteroid therapy, trigger point injections, and narcotic use for patients with chronic pain. Spinal stenosis is common in the older population, and more drug trials are needed for this condition.