Topic
Analgesic
About: Analgesic is a research topic. Over the lifetime, 19691 publications have been published within this topic receiving 664773 citations. The topic is also known as: painkiller & analgesic agent.
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TL;DR: The formalin test is a statistically valid technique which has two advantages over other pain tests:: (1) little or no restraint is necessary, permitting unhindered observation of the complete range of behavioral responses; and, (2) the pain stimulus is continuous rather than transient, thus bearing greater resemblance to most clinical pain.
Abstract: SUMMARYA method for assessing pain and analgesia in rats and cats is described. The procedure involves subcutaneous injection of dilute formalin into the forepaw, after which the animal's responses are rated according to objective behavioral criteria. The formalin test is a statistically valid techn
2,573 citations
TL;DR: It is suggested that the early phase is due to a direct effect on nociceptors and that prostaglandins do not play an important role during this phase, and the late phase seems to be an inflammatory response with inflammatory pain that can be inhibited by anti‐inflammatory drugs.
Abstract: The formalin test in mice is a valid and reliable model of nociception and is sensitive for various classes of analgesic drugs. The noxious stimulus is an injection of dilute formalin (1% in saline) under the skin of the dorsal surface of the right hindpaw. The response is the amount of time the animals spend licking the injected paw. Two distinct periods of high licking activity can be identified, an early phase lasting the first 5 min and a late phase lasting from 20 to 30 min after the injection of formalin. In order to elucidate the involvement of inflammatory processes in the two phases, we tested different classes of drugs in the two phases independently. Morphine, codeine, nefopam, and orphenadrine, as examples of centrally acting analgesics, were antinociceptive in both phases. In contrast, the non-steroid anti-inflammatory drugs indomethacin and naproxen and the steroids dexamethasone and hydrocortisone inhibited only the late phase, while acetylsalicylic acid (ASA) and paracetamol were antinociceptive in both phases. The results demonstrate that the two phases in the formalin test may have different nociceptive mechanisms. It is suggested that the early phase is due to a direct effect on nociceptors and that prostaglandins do not play an important role during this phase. The late phase seems to be an inflammatory response with inflammatory pain that can be inhibited by anti-inflammatory drugs. ASA and paracetamol seem to have actions independent of their inhibition of prostaglandin synthesis and they also have effects on non-inflammatory pain.
2,092 citations
TL;DR: The adequacy of prescribed analgesic drugs using guidelines developed by the World Health Organization was assessed, the factors that influenced whether analgesia was adequate were studied, and the effects of inadequate analgesia on the patients' perception of pain relief and functional status were determined.
Abstract: Background and Methods Pain is often inadequately treated in patients with cancer. A total of 1308 outpatients with metastatic cancer from 54 treatment locations affiliated with the Eastern Cooperative Oncology Group rated the severity of their pain during the preceding week, as well as the degree of pain-related functional impairment and the degree of relief provided by analgesic drugs. Their physicians attributed the pain to various factors, described its treatment, and estimated the impact of pain on the patients' ability to function. We assessed the adequacy of prescribed analgesic drugs using guidelines developed by the World Health Organization, studied the factors that influenced whether analgesia was adequate, and determined the effects of inadequate analgesia on the patients' perception of pain relief and functional status. Results Sixty-seven percent of the patients (871 of 1308) reported that they had had pain or had taken analgesic drugs daily during the week preceding the study, and 36 percen...
2,002 citations
University of Rochester1, University of Wisconsin-Madison2, University of Pennsylvania3, Aarhus University Hospital4, Helsinki University Central Hospital5, University of Washington6, University of California, San Francisco7, University of Liverpool8, Beth Israel Medical Center9, Imperial College London10, Oregon Health & Science University11, University of Mainz12, University of California, San Diego13
TL;DR: Patients with neuropathic pain are challenging to manage and evidence‐based clinical recommendations for pharmacologic management are needed, and medications should be individualized, considering side effects, potential beneficial or deleterious effects on comorbidities, and whether prompt onset of pain relief is necessary.
Abstract: Patients with neuropathic pain (NP) are challenging to manage and evidence-based clinical recommendations for pharmacologic management are needed. Systematic literature reviews, randomized clinical trials, and existing guidelines were evaluated at a consensus meeting. Medications were considered for recommendation if their efficacy was supported by at least one methodologically-sound, randomized clinical trial (RCT) demonstrating superiority to placebo or a relevant comparison treatment. Recommendations were based on the amount and consistency of evidence, degree of efficacy, safety, and clinical experience of the authors. Available RCTs typically evaluated chronic NP of moderate to severe intensity. Recommended first-line treatments include certain antidepressants (i.e., tricyclic antidepressants and dual reuptake inhibitors of both serotonin and norepinephrine), calcium channel alpha2-delta ligands (i.e., gabapentin and pregabalin), and topical lidocaine. Opioid analgesics and tramadol are recommended as generally second-line treatments that can be considered for first-line use in select clinical circumstances. Other medications that would generally be used as third-line treatments but that could also be used as second-line treatments in some circumstances include certain antiepileptic and antidepressant medications, mexiletine, N-methyl-D-aspartate receptor antagonists, and topical capsaicin. Medication selection should be individualized, considering side effects, potential beneficial or deleterious effects on comorbidities, and whether prompt onset of pain relief is necessary. To date, no medications have demonstrated efficacy in lumbosacral radiculopathy, which is probably the most common type of NP. Long-term studies, head-to-head comparisons between medications, studies involving combinations of medications, and RCTs examining treatment of central NP are lacking and should be a priority for future research.
1,962 citations
TL;DR: Chemotherapy with mitoxantrone and prednisone provides palliation for some patients with symptomatic hormone-resistant prostate cancer and most responding patients had an improvement in quality-of-life scales and a decrease in serum prostate-specific antigen (PSA) level.
Abstract: PURPOSETo investigate the benefit of chemotherapy in patients with symptomatic hormone-resistant prostate cancer using relevant end points of palliation in a randomized controlled trial.PATIENTS AND METHODSWe randomized 161 hormone-refractory patients with pain to receive mitoxantrone plus prednisone or prednisone alone (10 mg daily). Nonresponding patients on prednisone could receive mitoxantrone subsequently. The primary end point was a palliative response defined as a 2-point decrease in pain as assessed by a 6-point pain scale completed by patients (or complete loss of pain if initially 1 +) without an increase in analgesic medication and maintained for two consecutive evaluations at least 3 weeks apart. Secondary end points were a decrease of > or = 50% in use of analgesic medication without an increase in pain, duration of response, and survival. Health-related quality of life was evaluated with a series of linear analog self-assessment scales (LASA and the Prostate Cancer-Specific Quality-of-Life I...
1,566 citations