Neck Pain in Adults _________________________________________________________________________
PHARMACOTHERAPIES Standard practice guidelines recommend the following analgesic options for acute/subacute neck pain [7; 102; 103]: • Acetaminophen • NSAIDs
Assessment of Analgesic Response Assessing treatment response to neck pain pharmacotherapy is very important. This requires the patient reaching and maintaining adherence to a target dose at which therapeutic effect is expected for at least two weeks. The most common errors are underdosing and insufficient treatment duration [71]. Assess treatment response using a 0–10 scale, and use the results to help guide treatment planning [71]. With a pain reduction to <3, continue monotherapy and consider indication for combination therapy, when appropriate. For a pain reduction by ≥30% but a pain intensity ≥4, combine the existing therapy with an additional first-line drug. If pain is reduced by <30% and the pain intensity ≥4, the drug should be considered ineffective and the patient should be switched to another first-line agent. It is also important to check for side effects [71]. If intolerable side effects prevent effective dosing, switch to another drug. If the patient is taking a clinically effective dose but intolerable side effects continue, lower the dose before switching analgesics. Depending on the therapeutic and side effects after this is done, try switching the drug or starting combination therapy with a low dose of the original drug. If the pain relief remains inadequate, consult a pain specialist or refer the patient to a pain center. Acetaminophen Acetaminophen (paracetamol) is a nonsalicylate antipyretic analgesic recommended as first-line therapy in mild-to-moderate acute or chronic low back, spinal, and musculoskeletal pain [124; 125; 126]. Enduring assumptions of its efficacy and safety were first challenged by a randomized controlled trial of 1,649 patients with acute low back pain. Following 28 days of acetaminophen or placebo taken as regular dosing (three times per day) or as needed for pain, acetaminophen did not differ from placebo on any pain outcome, average time to recovery, or tablets consumed per day [125]. Reviews of placebo-controlled trials concluded that acetaminophen was ineffective in reducing pain and disability in low back pain and showed little evidence of efficacy in diverse chronic pain conditions. Even 4,000 mg/day for 1 to 12 weeks had no effect beyond placebo on pain, quality of life, function, or sleep quality in acute low back pain, and any effect in chronic low back pain was uncertain [124; 126; 127]. A caveat is that very few studies have evaluated acetaminophen in neck pain. Acetaminophen shows a significant dose-response effect for increased risks of cardiovascular, renal, and GI adverse effects, suggesting considerable toxicity risk, especially at the upper end of standard analgesic dosing [128]. Acetaminophen may cause liver failure in acute overdose or chronic excessive exposure [129]. The universal endorsement and routine use of acetaminophen as first-choice analgesic in acute and chronic neck pain is questioned [124; 125; 126].
• Muscle relaxants • Opioid analgesics
Chronic neck pain management is more difficult and complex, but pharmacotherapy guidelines for chronic neck pain are non-existent, and general guidelines for the management of chronic pain may be unhelpful. Practice guidelines recommend drug and non-drug therapies based on randomized controlled trials, considered the best study design to detect efficacy. Analgesic randomized controlled trials are usually placebo-controlled. Systematic reviews examine treatment efficacy by pooling the results of randomized controlled trials to measure differences in average response to treatment versus comparator/placebo [118]. Systematic reviews of guideline-recommended analgesics for neck pain have found acetaminophen ineffective and NSAIDs minimally effective, compared with placebo. Systematic reviews have also found minimal benefit in other analgesics considered effective. These results may reflect true ineffectiveness or possible limitations with randomized controlled trial evaluation of analgesics, including [119; 120]: • Rigid protocols that disallow dose adjustments when ineffective or intolerable • Strict enrollment criteria, with outcomes of research subjects dissimilar to typical patients • Increasing placebo-response rates that require larger studies to show relevant differences from placebo In some cases, it is not the study design but the paradigm itself that limits usefulness. Randomized controlled trials have evaluated analgesic efficacy in patients with specific pathologies (e.g., disk herniation, degenerative processes). The efficacy of oral analgesics is mostly unrelated to underlying tissue pathology, which can produce diverse pain mechanisms. Pain mechanism targeting is now emphasized [69; 70]. Central sensitization is recognized to underlie many chronic neck pain cases and is very difficult to treat. Optimized pain reduction can require combining medications that target peripheral inputs in the dorsal horn (bottom-up) and descending pain modulation pathways (top-down) with tapentadol (opioid and norepinephrine reuptake inhibitor) or opioids plus NSAIDs, norepinephrine reuptake inhibitors, or anticonvulsants. Adding topical analgesics can help decrease peripheral nociceptive input [69; 96; 121; 122]. A 2017 practice guideline recommended combining analgesics in chronic pain treatment [123].
48
MDKY1626
Powered by FlippingBook