Efficacy, acceptability, and safety of muscle relaxants for adults with non-specific low back pain: systematic review and meta-analysis

Review of 49 trials noted very low and low certainty evidence showing that non-benzodiazepine antispasmodics might provide small but not clinically important reductions in pain intensity at or before 2 weeks and might increase risk of ADR in acute low back pain, respectively.

Source:

British Medical Journal