Diazepam Does Not Help Acute Low Back Pain
Diazepam is not recommended for acute low back pain—it provides no meaningful benefit over placebo and causes significant sedation and other central nervous system side effects. 1, 2
Evidence Against Diazepam for Acute Low Back Pain
The highest quality evidence comes from the 2017 American College of Physicians clinical practice guidelines, which synthesized multiple trials specifically evaluating benzodiazepines for low back pain 1, 2:
For acute nonradicular low back pain: A high-quality trial (n=50) found no difference between diazepam and placebo in pain relief at 5 days (76% vs 72%; RR 1.06) 1
For acute radicular pain: A good-quality trial showed diazepam was actually inferior to placebo—patients receiving diazepam were less likely to achieve ≥50% pain relief at 1 week (41% vs 79%; RR 0.5) and showed no functional improvement on the Roland-Morris Disability Questionnaire at 1 week or 1 year 1, 2
Most recent systematic review (2024): Using the rigorous REB method, diazepam demonstrated no efficacy for acute low back pain with or without radiculopathy 3
Harm Profile
Benzodiazepines consistently cause more adverse effects than placebo, particularly:
- Central nervous system effects (somnolence, fatigue, lightheadedness) 1
- Drowsiness (29% with diazepam vs 4% with other muscle relaxants in one ED trial) 4
- Risk for addiction, abuse, and overdose (though not systematically studied in these trials) 1
FDA Indication Context
While the FDA label lists diazepam as "useful adjunct for relief of skeletal muscle spasm due to reflex spasm to local pathology" 5, this broad indication predates modern evidence standards. The controlled trial evidence specifically for low back pain does not support this indication.
Clinical Bottom Line
Even when combined with NSAIDs or analgesics, diazepam adds no clinically meaningful benefit for acute low back pain while substantially increasing sedation risk. A 2022 emergency department study of 4 randomized trials found no SMR (including diazepam) improved outcomes more than placebo when patients also received NSAIDs 6.
For acute low back pain with presumed muscle spasm, use NSAIDs alone rather than adding diazepam. The muscle spasm theory of low back pain is not supported by evidence showing benzodiazepines provide benefit.