Is it safe for a 70-year-old female with back pain due to muscle spasm to take cyclobenzaprine (flexeril) 5mg three times a day (tid) as needed (prn)?

Cyclobenzaprine Use in a 70-Year-Old Female with Back Pain Due to Muscle Spasm

Cyclobenzaprine 5mg three times daily as needed is not recommended for a 70-year-old female with back pain due to muscle spasm due to increased risk of adverse effects in elderly patients. 1

Risks of Cyclobenzaprine in Elderly Patients

Cyclobenzaprine is essentially identical to amitriptyline in structure, with similar adverse effect profiles that pose particular concerns for older adults:

• The American Geriatrics Society identifies cyclobenzaprine as a potentially inappropriate medication (PIM) for older adults 1, 2
• Increased risk of falls due to sedation and dizziness
• Anticholinergic effects (dry mouth, constipation, urinary retention)
• Cognitive impairment and confusion
• FDA labeling specifically notes that plasma concentration of cyclobenzaprine is increased in the elderly 3

Alternative Recommendations for Muscle Spasm in Elderly

For a 70-year-old with back pain due to muscle spasm, consider these safer alternatives:

1. Non-pharmacological approaches first:

   • Heat therapy
   • Physical therapy
   • Gentle stretching exercises
   • Massage therapy 1

2. If medication is necessary:

   • Acetaminophen on a scheduled basis for moderate musculoskeletal pain 1
   • Topical analgesics (like diclofenac) which have better safety profiles in elderly patients 1

3. If muscle relaxant is absolutely required:

   • Baclofen at a very low starting dose (2-5mg once or twice daily) with careful monitoring 2
   • Limit treatment duration to 2-3 weeks maximum 2

Why Cyclobenzaprine Should Be Avoided

The FDA label for cyclobenzaprine specifically cautions:

"The plasma concentration of cyclobenzaprine is increased in the elderly... The elderly may also be more at risk for CNS adverse events such as hallucinations and confusion, cardiac events resulting in falls or other sequelae, drug-drug and drug-disease interactions." 3

Even at the lower 5mg dose, cyclobenzaprine carries significant risks in elderly patients. While the FDA states that "in the elderly, cyclobenzaprine should be used only if clearly needed" and "should be initiated with a 5 mg dose and titrated slowly upward" 3, the American Geriatrics Society guidelines recommend avoiding it altogether in favor of safer alternatives 1.

Monitoring If Cyclobenzaprine Must Be Used

If no alternatives are viable and cyclobenzaprine must be used:

• Start with 5mg once daily (not three times daily) 3
• Monitor for:
  • Sedation and dizziness
  • Cognitive changes
  • Falls risk
  • Urinary retention
  • Dry mouth and constipation
• Limit duration to less than 2 weeks 3
• Avoid combining with other CNS depressants or medications with anticholinergic properties

Remember that the efficacy of cyclobenzaprine for back pain is modest at best, with the greatest effect occurring in the first few days of treatment 4. This limited benefit does not outweigh the significant risks in elderly patients.