tailieunhanh - Chapter 012. Pain: Pathophysiology and Management (Part 7)

Opioid and COX Inhibitor Combinations When used in combination, opioids and COX inhibitors have additive effects. Because a lower dose of each can be used to achieve the same degree of pain relief, and their side effects are nonadditive, such combinations can be used to lower the severity of dose-related side effects. Fixed-ratio combinations of an opioid with acetaminophen carry a special risk. Dose escalation as a result of increased severity of pain or decreased opioid effect as a result of tolerance may lead to levels of acetaminophen that are toxic to the liver. Chronic PainManaging patients with chronic pain. | Chapter 012. Pain Pathophysiology and Management Part 7 Opioid and COX Inhibitor Combinations When used in combination opioids and COX inhibitors have additive effects. Because a lower dose of each can be used to achieve the same degree of pain relief and their side effects are nonadditive such combinations can be used to lower the severity of dose-related side effects. Fixed-ratio combinations of an opioid with acetaminophen carry a special risk. Dose escalation as a result of increased severity of pain or decreased opioid effect as a result of tolerance may lead to levels of acetaminophen that are toxic to the liver. Chronic PainManaging patients with chronic pain is intellectually and emotionally challenging. The patient s problem is often difficult to diagnose such patients are demanding of the physician s time and often appear emotionally distraught. The traditional medical approach of seeking an obscure organic pathology is usually unhelpful. On the other hand psychological evaluation and behaviorally based treatment paradigms are frequently helpful particularly in the setting of a multidisciplinary pain-management are several factors that can cause perpetuate or exacerbate chronic pain. First of course the patient may simply have a disease that is characteristically painful for which there is presently no cure. Arthritis cancer migraine headaches fibromyalgia and diabetic neuropathy are examples of this. Second there may be secondary perpetuating factors that are initiated by disease and persist after that disease has resolved. Examples include damaged sensory nerves sympathetic efferent activity and painful reflex muscle contraction. Finally a variety of psychological conditions can exacerbate or even cause pain. There are certain areas to which special attention should be paid in the medical history. Because depression is the most common emotional disturbance in patients with chronic pain patients should be questioned about their mood appetite