First Line Treatment of Musculoskeletal and Neuropathic Pain
The new concerns raised about the safety of nonsteroidal anti-inflammatory agents (NSAIDs) has led to physicians rethinking treatment of both acute and chronic musculoskeletal pain.1,2,3 Combination pharmacologic approaches abound with analgesics, muscle relaxants, anti-depressants, sedative hypnotics, anxiolytics, topical agents and anticonvulsants offering viable alternative options. Establishing a rationale for treatment — based on diagnostic evaluation and advantages of certain types of treatment for selected patients — is essential for all clinicians evaluating and treating patients for their pain problems. Many alternatives may be utilized as adjuncts to analgesic medications with the alternative choices offering added benefits without the risk of diversion and abuse seen with opioid therapy.4,5
History of pain onset and precipitators facilitates more judicious use of diagnostic tests.Recumbent or nocturnal back pain must be taken more seriously regarding possible underlying malignancy or neurogenic claudication. Pain without antecedent trauma history makes one look for a disease process as an etiology for the pain complaints.
Physical examination to detect localized tenderness, swelling, spasm or neurologic deficit offers great value in deciding the need for X-ray, MRI, CT or other imaging studies. Electrodiagnostic evaluation often is helpful in those individuals with neurologic involvement associated with pain complaints. Such testing can include electromyography (EMG), nerve conduction velocity (NCV), or somatosensory evoked potentials (SSEP).
The patients who should be started on nonsteroidal anti-inflammatory drugs for their pain are those with obvious swelling, inflammation, or those who suffered an acute injury or have a known inflammatory disease process. A logical extension of this reasoning means that many with neck or back pain complaints and those with chronic peripheral pain should not be taking NSAIDs and can thus avoid the expense and morbidity which is associated with their use.
Treatment with Nonsteroidal Anti-Inflammatory Agents
Individuals who need NSAIDs should not be randomly given a particular NSAID nor should all patients be started on the same NSAID. While cost and formulary issues may be important, there should be additional factors in picking the right drug for a particular patient.
Selective COX-2 inhibiting NSAIDs were thought to be the drug of choice because of indications of lessened gastrointestinal bleeding complications until recent studies raised concerns about cardiac side effects in Vioxx®, Bextra® and Celebrex® users.1,2,3 Significant serious reactions such as Stevens-Johnson syndrome also played a role in the recent withdrawal of Bextra by Pfizer,6 following the earlier voluntary withdrawal of Vioxx by Merck amid reports of increased risk of heart attacks and strokes.7
Despite much publicity about concerns for users of these drugs, a recent FDA Advisory Panel still recommended, by a 31 to 1 vote, to keep Celebrex on the market and, by narrow margins, recommended continued availability of both Vioxx and Bextra with appropriate warnings.8 Celebrex can still be safely prescribed to those who are not allergic to sulfa drugs and who limit chronic use to 200mg daily, a dosage that appears to be safe and without any increased cardiac risk. It still might be used for stiffness and swelling associated with pain, particularly in those who might be unable to tolerate other NSAIDs, including many elderly patients, those with increased gastrointestinal bleeding risk, or those on concomitant anticoagulant therapy.
The long-term safety of other newer NSAIDs is not yet known. Studies have yet to be done confirming the lack of potential cardiac concerns for Mobic. Even some older NSAIDs and those sold over the counter need to be monitored as more is learned about cardiac disease factor risks. Patients using prophylactic low dose aspirin also must be advised regarding the potential interference of agents such as ibuprofen with the anti-platelet function of the low dose aspirin.
Treatment with Muscle Relaxants
Outcome-based assessment of acute neck and back pain treatment clearly shows benefit with muscle relaxants and can shorten recovery by around two days.9 Recent reports indicate the lack of additive benefit through combination of ibuprofen with an effective dose of cyclobenzaprine, further strengthening the argument against addition of NSAIDs for acute neck and back pain.10
Soma10 should generally be avoided for new muscle relaxant prescriptions. It is metabolized to meprobamate, is habit forming, and has abuse potential with value as a street drug.
Pill splitting does not offer a convincing reason for selection of generic cyclobenzaprine at a 10mg dose versus the brand name 5mg dose. There is a lowered sedation and lowered discontinuation rate with similar efficacy using the 5mg dose.9 Splitting the 10 mg pills in an effort to match the efficacy and side effect profile of the brand name cyclobenzaprine11 may unfortunately result in varying dose levels which may be less than the effective dose or high enough to increase side effects leading to possible discontinuation of the drug prior to achieving treatment goals.
Cost may preclude selection of Skelaxin.10 While it may offer some benefit by providing sedation although its efficacy, relaxing muscles has not been clearly demonstrated.
Antidepressant, Sedative Hypnotic and Anxiolytic Use
A key question to ask a pain patient is whether they have problems falling or staying asleep. For those with difficulty falling asleep, use of a benzodiazepine or sedative hypnotic sleep aid is appropriate. For those with early morning awakening, additional questions should address possible depression associated with pain that might merit use of an antidepressant medication. For those with neuropathic pain,12 many physicians now favor amitryptiline or nortryptoline — with the latter having less side effects for many.
The newer antidepressant duloxetine (Cymbalta®)14 would appear to be the agent of choice in a diabetic with neurogenic pain. Many physicians are now attempting to assess if the unique benefit of reduction in nerve pain seen in diabetics will generalize to helping a variety of other painful neuropathic conditions beyond the current FDA-approved product indications.