The research on the benefits of analgesics in acute lower back pain remains ambiguous as per study findings released in BMJ.

Although analgesics are suggested as a second-line treatment in treating acute, nonspecific lower back pain however, there is no definitive advice on which one is better. Researchers carried out a systematic review and meta-analysis to assess the efficacy and safety of using analgesics to treat acute lower back pain.

The studies were controlled studies that tested analgesics to one another, in combination with either a placebo or no treatment. The medications that were considered to be analgesic comprised nonsteroidal anti-inflammatory medicines (NSAIDs) opioids, paracetamol and anticonvulsants, antidepressants and skeletal muscles relaxants, as well as corticosteroids.

The researchers accessed 5 databases and three registry of clinical trials (Medline, PubMed, Embase, CINAHL, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, EU Clinical Trials Register as well as the WHO’s International Clinical Trial Registry Platform) and identified 98 trials to be analysed.

The relative effectiveness and safety of analgesics for non-specific acute low back pain is a mystery.

The study was conducted in adults suffering from acute lower back pain. The medications were given systemically for a minimum of 24 hours. Any nonsystemic analgesics were not included in the study.

The main outcomes included the safety of patients as well as the lower back pain intensity, rated by a scale from zero to 100 at the conclusion of treatment. Other outcomes included severe adverse events, decreased back performance, and a cessation of treatment.

In 741 comparisons of medications 87% of comparisons had extremely low confidence. Thirteen percent had low confidence when it came to the reduction of pain. Some medications with low or low confidence in the reduction of pain included tolperisone (mean difference, -26.1; 95% confidence interval, -34.0 to -18.2) Aceclofenac and the tizanidine (mean change, -26.1; 95% C.I, -38.5 to -13.6) Pregabalin (mean change, -24.7; 95% C.I, -34.6 to -14.7) and 14 other medications when compared to placebo.

Of the 98 studies that were included in this research, 68 trials examined adverse drug reactions. There’s a moderate to low confidence in evidence of a higher risk of adverse events in people who are taking tramadol (risk ratio [RR(RR), 2.6 95% CI, 1.5-4.5), paracetamol with sustained-release tramadol (RR, 2.4; 95 percent 95% CI, 1.5-3.8), baclofen (RR, 2.3; 95 percent CI 1.5-3.4) and paracetamol and tramadol (RR, 2.1; 95 percent 95% CI, 1.3-3.4) compared with placebo.

Safety was evaluated in 46 trials, and direct evidence was discovered for 171 analgesic comparatives. From these comparisons four percent had very poor confidence. 65% had very low-confidence, a mere 29% had moderately confident, and 33% were high confidence.

Notably, some negative reactions were attributed to the use of nonselective NSAIDs, strong opioids and paracetamol (RR, 1.9; 95 percent CI, 1.1-3.2 High confidence) strong opioids and paracetamol (RR, 1.9; 95 percent CI, 1.3-2.7 moderate confidence) and nonselective NNSAIDs and an antispasmodic nonbenzodiazepine (RR, 1.5; 95% CI 1.1-2.1 moderately confident).

“The structure of this data isn’t yet adequate to guide clinical decision-making and the potential of meta-analysis of networks to improve estimates of effects was not realized,” the researchers noted. “Most estimates were derived from indirect evidence, which is a major reason for the very low or inadequate confidence.”

The limitations of the study included the possibility of bias across all studies, the lack of data as well as the inability to evaluate the impact of possible influence moderators.

The researchers concluded that “The efficacy and safety of analgesics for low back pain that is not specific and acute back pain is a mystery.”


Disclosure: Certain study authors have disclosed affiliations with pharmaceutical, biotech and/or device manufacturers. Check the original source for a complete listing of disclosures made by authors.

References:

Wewege MA, Bagg MK, Jones MD, et al. Comparative effectiveness and the safety of analgesics for adults suffering from acute lower back pain Review of systematics as well as a network-wide meta-analysis. BMJ. Published online March 22, 2023. doi:10.1136/bmj-2022-072962