What is the best nonsteroidal anti-inflammatory drug (NSAID) for an otherwise healthy adult with acute low-back pain?

Best NSAID for Acute Low Back Pain

For an otherwise healthy adult with acute low back pain, use diclofenac as the first-line NSAID, as it has the strongest evidence of efficacy among all NSAIDs studied. 1

Primary Recommendation

The most recent high-quality systematic review and meta-analysis from 2026 specifically evaluated six commonly used NSAIDs (celecoxib, diclofenac, etoricoxib, ibuprofen, ketoprofen, and naproxen) and found that only diclofenac demonstrated "solid evidence of efficacy" for acute low back pain 1. While ibuprofen and naproxen showed "conclusive evidence requiring confirmation," diclofenac stands alone with the strongest evidence base.

Supporting Evidence Framework

Why Diclofenac Over Other NSAIDs

• Diclofenac is the only NSAID with solid evidence specifically for acute low back pain 1
• The 2026 meta-analysis included 3,784 patients and used rigorous REB methodology to assess evidence quality 1
• While the effect size is small and may not be clinically dramatic, it represents the best available option among NSAIDs

General NSAID Efficacy

The 2017 ACP guideline systematic review established that NSAIDs as a class provide:

• Small to moderate short-term pain relief for acute low back pain 2
• Benefits that are generally short-term in duration 2

A 2020 Cochrane review confirmed:

• Moderate quality evidence for slight pain reduction (VAS difference of -7.29 points) 3
• High quality evidence for slight disability improvement (RMDQ difference of -2.02 points) 3
• These effects, while statistically significant, are small and may not be clinically transformative 3

Alternative NSAIDs When Diclofenac Is Unavailable

Second-Line Options:

• Ibuprofen: Has "conclusive to be confirmed" evidence for acute low back pain without radiculopathy 1
• Naproxen: Has "conclusive to be confirmed" evidence specifically for acute low back pain WITH radiculopathy 1; offers the advantage of 14-hour half-life allowing twice-daily dosing with reduced pill burden 4
• Aceclofenac: Demonstrated favorable safety profile and lower risk of chronicity/recurrence compared to other NSAIDs in a 2024 study 5

COX-2 Selective NSAIDs:

There is no advantage to using selective COX-2 inhibitors (celecoxib, etoricoxib) over traditional NSAIDs for pain relief:

• Low quality evidence shows no difference in pain reduction between COX-2 and non-selective NSAIDs 3
• While COX-2 inhibitors may have fewer gastrointestinal side effects in short-term trials 6, they carry cardiovascular risks in certain populations 6
• Etoricoxib was found cost-effective in one small study 7, but lacks the solid efficacy evidence that diclofenac possesses

Critical Caveats

What NOT to Use:

• Acetaminophen is ineffective for acute low back pain based on new evidence 2 - this contradicts older guidelines
• Avoid opioids - evidence limited to modest short-term effects with known addiction/overdose risks 2, 4
• Skeletal muscle relaxants cause sedation without improving functional recovery 2, 4

Safety Considerations:

• All NSAIDs carry gastrointestinal and cardiovascular risks
• The evidence on adverse events is very low quality, as most trials were short-term and not designed to capture rare or long-term harms 3
• Dexketoprofen showed higher gastrointestinal adverse events 5
• Lornoxicam showed higher cardiovascular adverse events 5

Realistic Expectations:

• Pain relief will be small to moderate at best 2
• Benefits are primarily short-term (days to weeks) 2
• Effect sizes, while statistically significant, may not feel clinically meaningful to patients 3

Practical Algorithm

1. First choice: Diclofenac (standard dosing for 7-10 days)
2. If radiculopathy present: Consider naproxen as alternative 1
3. If GI concerns: Consider aceclofenac (better GI tolerability profile) 5
4. If twice-daily dosing preferred: Naproxen (longer half-life) 4
5. Avoid: Acetaminophen, opioids, COX-2 inhibitors (unless specific GI history warrants)

The evidence consistently shows that no single NSAID is dramatically superior to others 2, 3, 6, but diclofenac has the most robust evidence specifically for acute low back pain 1.