Topical reviewChronic Pain: Pathophysiology and Treatment Implications
Section snippets
What Is Chronic Pain?
Chronic pain has been defined as aberrant somatosensory processing in the peripheral or central nervous system (CNS) that is sustained beyond the normally expected time course relative to the stimulus. This definition, although helpful, provides only part of the story. Chronic pain is often insidious, vague, and difficult to pinpoint. Chronic pain may arise from a primary dysfunction within the nervous system. Chronic pain is difficult to diagnose by health care professionals, and its diagnosis
Therapeutic Implications
Better understanding of the pathophysiology associated with chronic pain will introduce the challenges to finding effective treatments and plant the seeds to nurture novel approaches in this quest. Drugs that are effective for acute pain may have little or no benefit when used for chronic pain syndromes. Conversely, drugs with little demonstrated benefit in treatment of operative pain may have significant efficacy in the treatment of chronic pain. The long-term therapies typically instituted
Chronic Inflammatory Pain
Use of nonsteroidal antiinflammatory analgesics has become the hallmark of therapeutic interventions for mild to moderate chronic inflammatory pain in animals. By inhibiting production of COX enzymes, these agents decrease prostanoid production. Prostanoids are mediators of inflammation and amplify nociceptive input.9 Hyperalgesic responses to tissue injury are primarily ascribed to the effects of COX-2. Some drugs of this class, for example aspirin, may inhibit other significant promoters for
Cancer Pain
Pain in patients with cancer may be related to processes associated with the tumor itself or to the treatment of the disease. Nonsteroidal antiinflammatory analgesics aid in the reduction of inflammatory mediators that sensitize the pain pathways. Opioids constitute the backbone of treatment of moderate to severe cancer pain. Side effects associated with chronic administration of opioids include vomiting, dysphoria, diarrhea, or constipation. Dose-dependent analgesia from opioids is achieved
Neuropathic Pain
Neuropathic pain is pain originating in the nervous system. Traumatic damage to nervous tissue is a significant initiating factor in neuropathic pain. Additionally, ingredients in the “sensitizing soup” may activate macrophages at the site of nerve injury, resulting in production of tumor necrosis factor or interleukin-1β, substances that promote neuropathic pain. Features of neuropathic pain include: 1) central sensitization; 2) central disinhibition (imbalance in excitatory and inhibitory
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2014, Pain PracticeCitation Excerpt :Common symptoms of chronic pain are spontaneous burning pain, tactile allodynia, and hyperalgesia.4 Chronic pain is a persistent pain that is either continuous or recurrent, and it effects the well-being, functioning, and quality of life of the patient.5 There are various physical (eg, neuromuscular, reproductive, gastrointestinal, urologic) ailments and/or psychological disorders (eg, major depression, hypochondriasis, conversion disorder) that may cause or contribute to chronic pain.