What can a patient order for back pain if they can’t take Tylenol (acetaminophen), Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), or opioids?

Alternative Pharmacologic Options for Back Pain

For patients unable to take acetaminophen, NSAIDs, or opioids, muscle relaxants are the primary pharmacologic option, with cyclobenzaprine 5 mg three times daily being the most evidence-based choice for short-term relief (up to 1-2 weeks). 1, 2

First-Line Recommendation: Muscle Relaxants

Cyclobenzaprine (Preferred Agent)

• Start with cyclobenzaprine 5 mg three times daily rather than the traditional 10 mg dose, as this provides equivalent efficacy with significantly less sedation. 3, 4
• The 5 mg dose is nearly 5 times more likely to produce symptom improvement compared to placebo by day 14, with a number needed to treat of approximately 3. 4
• Maximum benefit occurs within the first 3-4 days of treatment, with efficacy declining after the first week, so limit duration to 7-14 days maximum. 3, 4
• Patients experience improvement across all pain domains: local pain, muscle spasm, range of motion, tenderness, and activities of daily living. 4

Important Caveats for Cyclobenzaprine

• Central nervous system adverse effects are common, particularly drowsiness (dose-dependent), so warn patients about impaired driving and operating machinery. 1
• Avoid in elderly patients due to high risk of sedation, confusion, and falls. 5
• Use with caution in hepatic impairment; start with 5 mg and titrate slowly in mild impairment, avoid entirely in moderate-to-severe hepatic disease. 6
• Dry mouth is the second most common side effect after drowsiness. 6, 3

Alternative Muscle Relaxants

• Other non-benzodiazepine muscle relaxants (methocarbamol, metaxalone) can be considered if cyclobenzaprine is not tolerated, though evidence is less robust. 1
• Avoid carisoprodol due to metabolism to meprobamate with abuse potential. 1
• Avoid tizanidine unless spasticity is present, as it carries hepatotoxicity risk. 1

Second-Line Option: Tricyclic Antidepressants (Chronic Pain Only)

For Chronic Low Back Pain

• Tricyclic antidepressants (amitriptyline, nortriptyline) are an option for chronic low back pain when muscle relaxants have failed or are not appropriate. 1
• Start amitriptyline at 10-25 mg at bedtime and titrate slowly to 50-75 mg as tolerated. 7
• Avoid in elderly patients due to excessive anticholinergic effects (dry mouth, constipation, urinary retention, confusion) and fall risk. 5
• Sedative effects may appear before analgesic benefits, which can take up to 30 days to develop. 7

For Chronic Pain with Radiculopathy

• Gabapentin provides small, short-term benefits for radicular pain (sciatica), though it has not been directly compared to other treatments. 1
• This is particularly relevant if the back pain has a neuropathic component with leg radiation.

Third-Line Option: Duloxetine (Chronic Pain, Specific Populations)

• Duloxetine 30-60 mg daily is recommended for chronic low back pain, particularly in older adults with renal impairment where other options are limited. 5
• Start with 30 mg daily for one week, then increase to 60 mg daily if tolerated. 5
• This SNRI has a favorable safety profile compared to tricyclic antidepressants in older adults. 5

Critical Clinical Considerations

What NOT to Use

• Avoid benzodiazepines as muscle relaxants for back pain—they lack evidence for efficacy and carry significant risks of dependence, sedation, and falls. 1
• Tramadol should be avoided in this scenario since it has weak opioid properties and the patient cannot take opioids. 1

Duration of Therapy

• Limit muscle relaxants to 1-2 weeks maximum as efficacy declines after the first week and adverse effects accumulate. 1, 3
• For chronic pain requiring longer treatment, transition to tricyclic antidepressants or duloxetine rather than continuing muscle relaxants. 1, 5

Monitoring

• Assess for central nervous system side effects (drowsiness, dizziness, confusion) at each follow-up, particularly in the first few days. 1, 6
• Reassess pain and function within 3-7 days; if no improvement, consider alternative diagnoses or non-pharmacologic interventions rather than escalating medications. 1, 2

Non-Pharmacologic Therapies (Essential Adjuncts)

• Physical therapy, structured exercise, spinal manipulation, massage, and cognitive behavioral therapy should be strongly recommended alongside any medication, as they improve outcomes without medication risks. 5, 8
• These interventions are particularly important when pharmacologic options are limited. 5