What is the best muscle relaxer for a patient with whiplash (cervical acceleration-deceleration injury) from skiing?

Best Muscle Relaxer for Whiplash Injury

For acute whiplash injury from skiing, cyclobenzaprine 5 mg three times daily is the recommended muscle relaxant, providing effective short-term pain relief with fewer sedative side effects than higher doses. 1, 2, 3

Evidence-Based Recommendation

Cyclobenzaprine 5 mg TID is superior to other dosing regimens for acute musculoskeletal spasm based on the following:

• Peak effectiveness occurs at 2-4 days, with skeletal muscle relaxants demonstrating moderate superiority to placebo for short-term pain relief in acute conditions 1, 2
• The 5 mg dose is as effective as 10 mg TID but with significantly lower incidence of sedation 3
• Clinical trials show statistically significant superiority over placebo for all primary endpoints (global impression of change, medication helpfulness, relief from pain) by day 3-4 and day 7 4, 3
• Efficacy is independent of sedation, as demonstrated by subanalysis showing meaningful treatment effects in patients who did not report somnolence 3

Dosing and Duration

• Start with 5 mg three times daily for 7 days 4, 3
• The 2.5 mg TID dose was not significantly more effective than placebo and should be avoided 3
• Treatment duration should not exceed 2 weeks in most cases, as clinical trials consistently evaluated durations of 2 weeks or less 1, 2
• Onset of relief is apparent within 3-4 doses of the 5 mg regimen 3

Combination Therapy Considerations

Cyclobenzaprine monotherapy is as effective as combination therapy with NSAIDs:

• A randomized trial comparing cyclobenzaprine 5 mg TID alone versus combination with ibuprofen (400 mg or 800 mg TID) showed no significant differences in patient global impression of change after 7 days 5
• While combination therapy with NSAIDs is well-tolerated, it is associated with more side effects (primarily drowsiness) without additional benefit 4, 5
• If NSAIDs are added, they do not enhance the clinical effect of cyclobenzaprine in acute musculoskeletal conditions 4

Important Caveats

Avoid prolonged use beyond acute phase:

• There is insufficient evidence to support skeletal muscle relaxants for chronic pain, with only Category D evidence rating for chronic conditions 2
• Literature is inadequate to evaluate efficacy beyond 2-3 weeks 1, 2

Common adverse effects are dose-related:

• Somnolence and dry mouth are most common, occurring in approximately 54-62% of patients on 5-10 mg doses versus 35% on placebo 3
• These effects are mild and dose-related, making the 5 mg dose preferable 3

Special populations:

• Use with caution in hepatic impairment, starting with 5 mg and titrating slowly 4
• Not recommended in moderate to severe hepatic insufficiency 4

Clinical Context for Whiplash

Whiplash (cervical acceleration-deceleration injury) typically results in soft tissue injuries with pain, stiffness, and tenderness developing with latency of several hours 6, 7. The prognosis is favorable with recovery in over 90% of injured subjects 8. Rational management includes rest, heat, analgesics, muscle relaxants, and isometric exercises 6.