Musculoskeletal 2

In a patient who was rear-ended and experienced immediate neck pain with decreased ROM but no focal neurologic problems, what is the usefulness of muscle relaxants in getting the patient back to work as a transportation worker?

• Side effects: all cause significant drowsiness, do not drive or operate heavy machinery, use with caution in patients with liver/kidney disease
• Baclofen (GABA-agonist) and tizanidine (a2-agonist) approved for spasticity and sometimes used for msk pain
• Metaxalone (Skelaxin): low side effects, no sedation, some double blind placebo studies showing positive effects of reducing back pain
• Cyclobenzaprine: structurally similar to TCAs, sedation, anticholinergic effects, more effective when used in combo with NSAIDs
• Carisoprodol (Soma): sedation, no reproducible benefits, reports of abuse and impaired driving


How can NSAIDs be used to treat the above patient?

• NSAIDs work by inhibiting COX-2 activity
• Side effects: GI bleeding, renal dysfunction, platelet inhibition, cardiovascular effects
• Celecoxib: COX-2 specific
• Meloxicam and etodolac: COX-2 selective


What is a medication treatment algorithm for acute pain in a worker who fell off a ladder, injuring his foot and ankle?

• Tylenol: has equivalent analgesia to NSAIDs for ortho injuries, liver toxicity
• Ibuprofen 800-1200mg per day has excellent safety profile --> higher dose associated with more side effects
• Opioids can be used for acute mod-severe pain, more effective with Tylenol
• Codeine metab by cyt P450, which is lacking in 10% of whites --> poor efficacy
• Tramadol: central analgesic with low affinity for opioid receptors, inhib NE and serotonin reuptake, less likely to lead to dependence


What is the rationale for use of topical analgesics to treat lateral epicondylitis in a 50 year old secretary?

• Topical meds: high concentration in dermis, muscle, and penetration into synovial fluid, can have local cutaneous reaction
• No studies to address topical opioids for acute msk pain
• Capsaicin: induces analgesia via desensitization from substance P and activates vanilloid receptors --> benefits in postherpetic neuralgia, trigem neuralgia, cluster HA, OA, not useful for acute pain
• Lidoderm: more evidence in chronic pain