Acute Back Pain: Skip the Prescription Painkillers in First Line, Study Suggests

— Opioids and gabapentin double the risks for OUD and overdose versus nondrug therapies

Patients with acute low back pain (LBP) who got opioids or gabapentinoids as initial therapy faced twice the risk of opioid use disorder (OUD) or overdose compared with other first-line treatments, nationwide Medicaid data showed.

Compared with not starting with an opioid, those who initiated one at doses below 50 mg in morphine equivalents, but for at least 7 days, saw a 105.2% increase in likelihood of OUD or overdose (95% CI 89.0-121.4), according to Kara E. Rudolph, PhD, MPH, MHS, of Columbia University in New York City, and colleagues.

Risks for OUD and overdose were similarly increased with gabapentin-like drugs (101.6%, 95% CI 84.9-118.2), the group reported in JAMA Network Openopens in a new tab or window. Also, opioids started at high doses (>50 mg in morphine equivalents) came with even greater risk (146.6% increase versus not receiving an opioid, 95% CI, 121.5-171.7).

Meanwhile, Medicaid patients who instead started with manual, nondrug therapies were at significantly lower risk for subsequent OUD or overdose: by 32.8% (95% CI 26.8-38.9) with chiropractic and by 31.1% (95% CI, 22.1-40.1) with physical therapy, compared with not starting these types of therapy.

These findings provide additional support, if any was needed, for longstanding guidelines that recommend against powerful prescription painkillers as first-line treatment for acute LBP, the investigators said.

"Pharmacologic therapies can be considered after weighing potential benefits against longer-term risks," they added. "When opioids are prescribed, minimizing dose and duration remain prudent."

For well over a decade now, published guidelines have called for nonpharmacological therapies to be tried first for acute LBP, before going the drug route. Those came in the wake of the "opioid epidemic"opens in a new tab or window that saw soaring rates of overdoses, which followed earlier recommendations, influenced by opioid manufacturers, to regard pain as the "fifth vital sign"opens in a new tab or window that should be treated aggressively by any means necessary. When the crisis was finally recognized, gabapentinoids, a class that also includes pregabalin, began to be pushed as a substitute for opioids despite poor evidence of efficacy in low back pain.

Guidelines notwithstanding, recent studies have shown that first-line opioids remain commonly prescribed for acute LBP. Rudolph and colleagues pointed to work from 2017-2018 indicating that between 12% and 20% of patients with private insurance or Medicaid were given opioid prescriptions.

For the current study, the investigators pulled Medicaid data for 25 states that accepted the expanded eligibility authorized under the Affordable Care Act. (Maryland was excluded because diagnostic coding was deemed unreliable.) A total of 399,500 Medicaid enrollees were identified with a new diagnosis of acute LBP and had no record of opioid use in the recent past. Of these, 21.0% were prescribed an opioid within 1 month of diagnosis, and 5.8% were prescribed gabapentin or similar agent. About 35% were prescribed a nonpharmacological treatment including chiropractic, physical therapy, or massage therapy. Large numbers also received prescriptions for such treatments as anti-inflammatory and muscle relaxant medications, acetaminophen, or corticosteroids.

Mean patient age was 39 and 60% were women. Almost exactly half were white and 98% had income below 138% of the federal poverty level. Records for 2% indicated alcohol abuse and 7% had abused other, nonopioid substances, mostly nicotine.

Primary outcomes included diagnoses of OUD or overdose at months 7 and 13 after initial diagnosis of acute LBP -- that is, 6 and 12 months after being prescribed something. Overall, OUD/overdose occurred at cumulative rates of 1.4% and 2.3%, respectively. These were defined as subsequent diagnostic codes for opioid abuse, opioid dependence, opioid-involved overdose, or a prescription for medication for treating OUD. (In the report, Rudolph's group did not distinguish between OUD and overdose, making it unclear whether one had dominated the adverse outcomes.)

Only one form of drug treatment appeared to reduce the risk of OUD/overdose relative to not starting such therapy, and that was muscle relaxants (RR 0.87, 95% CI 0.82-0.92). Steroids and anti-inflammatories neither raised nor lowered the risk. Acetaminophen and benzodiazepines both increased the risk significantly (RR 1.35-1.38), though clearly less than for opioids or gabapentinoids. Massage therapy was associated with a slight risk reduction (RR 0.91, 95% CI 0.88-0.94).

These risks for patients who didn't start an opioid immediately came because more than 90,000 got an opioid prescription at some point, according to the Medicaid records, some 20% of them did so between months 1 and 3.

The study's chief limitation was its focus on Medicaid enrollees, who by definition are less affluent than the general population and perhaps more likely to be prescribed drug therapies for pain because of difficulties they and/or their physicians perceive in accessing other forms of care. Importantly too, use of nonprescription medications or drugs that patients paid out of pocket or used illicitly were not tracked. The reliance on diagnostic codes for treatment exposures and outcomes increases the chance of data errors. Patients' physical comorbidities were not included in the analysis. Finally, the records did not include data on the efficacy of any of the treatments provided; Rudolph and colleagues did note, however, that 12% of the cohort eventually transitioned to chronic LBP.