Are baclofen and pregabalin appropriate treatments for radiculopathy secondary to lumbar spondylosis?

Treatment of Radiculopathy Secondary to Lumbar Spondylosis with Baclofen and Pregabalin

Baclofen is not recommended for lumbar radiculopathy, while pregabalin may provide modest short-term benefit but has limited evidence and should not be considered first-line therapy. 1, 2

Baclofen: Not Recommended

• The American College of Physicians explicitly does not recommend baclofen as a preferred muscle relaxant for low back pain or radiculopathy. 2
• Tizanidine is considered superior to baclofen with a better safety profile if a muscle relaxant is needed for short-term use in acute exacerbations. 2
• Baclofen lacks evidence supporting efficacy specifically for radicular pain and should be avoided in this clinical scenario. 2

Pregabalin: Limited and Inconsistent Evidence

Efficacy Concerns

• Pregabalin shows no benefit for chronic nonradicular back pain and may actually worsen function, making it inappropriate for mechanical back pain without clear radicular features. 1
• A 2010 randomized controlled withdrawal trial found that pregabalin-treated patients did not differ significantly from placebo in time to loss of response in chronic lumbosacral radiculopathy, despite initial response rates of 58% during the single-blind phase. 3
• The evidence for pregabalin in lumbar radiculopathy is inconsistent, with effects on pain intensity ranging from 0.3 to 1.9 points on a 0-10 scale—clinically marginal improvements. 4
• Lumbosacral radiculopathy appears to be a relatively refractory condition to standard neuropathic pain medications, with limited response compared to other neuropathic pain conditions. 1

Comparative Data

• A 2024 meta-analysis found pregabalin statistically superior to gabapentin only at short-term follow-up (≤6 weeks), with a mean difference of -0.31 points—a clinically insignificant improvement. 5
• By 6-12 weeks, no difference exists between pregabalin and gabapentin in pain reduction. 5
• A 2022 study after transforaminal epidural steroid injection found no statistically significant differences in pain scores between pregabalin and gabapentin (P = 0.811). 6

Safety Concerns

• Pregabalin causes adverse effects on balance and gait at initial doses and during dose escalation, with significantly lower Tinetti Balance and Gait Test scores in the first week of treatment. 7
• Somnolence is the most common adverse effect, leading to 44% dropout rates even at the lowest dose (75 mg twice daily) in Asian populations. 8
• The combination of sedation, dizziness, and fall risk makes pregabalin particularly problematic in elderly patients. 1, 7

Recommended Treatment Algorithm

First-Line Therapy

• Start with NSAIDs (naproxen 500 mg twice daily or ibuprofen 600-800 mg three times daily) to target the inflammatory component of radicular pain. 1, 4
• Add gabapentin (not pregabalin) for the neuropathic component, starting at 100-300 mg daily and titrating to 1200-3600 mg/day in divided doses over 4-8 weeks. 1, 4
• Gabapentin shows small to moderate short-term benefits specifically for radicular pain, with a larger evidence base than pregabalin. 1, 4

Second-Line Therapy (If Insufficient Response After 4-6 Weeks)

• Add a tricyclic antidepressant (nortriptyline 10-25 mg nightly, titrating to 50-150 mg) or duloxetine 30-60 mg daily, as combination therapy with gabapentin has shown superiority over monotherapy. 1
• Nortriptyline is preferred over amitriptyline in elderly patients due to fewer anticholinergic side effects. 1
• Duloxetine is particularly useful if depression coexists. 1

Short-Term Adjunctive Therapy

• For acute exacerbations with severe muscle spasm, consider cyclobenzaprine (not baclofen) 5-10 mg at bedtime for ≤1-2 weeks only. 1
• Muscle relaxants have no evidence for efficacy beyond 2 weeks and should never be used for chronic pain. 1

Critical Pitfalls to Avoid

• Do not use baclofen for radiculopathy—it lacks evidence and is not recommended by major guidelines. 2
• Do not use pregabalin as first-line therapy—gabapentin has superior evidence and lower cost. 1, 4
• Do not prescribe pregabalin for nonradicular back pain—it may worsen function. 1
• Do not use systemic corticosteroids—they are ineffective compared to placebo for low back pain with or without sciatica. 1
• Do not use benzodiazepines—they are ineffective for radiculopathy and substantially increase fall risk. 1
• Do not expect dramatic pain relief from any medication—radiculopathy is relatively refractory to pharmacologic treatment, and realistic expectations should be set with patients. 1

Monitoring and Reassessment

• Reassess response to optimized gabapentin (1200-3600 mg/day) plus NSAIDs after 4-6 weeks. 1
• If pain remains uncontrolled despite optimized pharmacotherapy, refer to pain management or spine specialist for consideration of epidural steroid injections or surgical evaluation. 1
• Use time-limited courses for all medications, with regular reassessment of efficacy and side effects. 1, 4