Naloxone dose dependently produces analgesia and hyperalgesia in postoperative pain.
ABSTRACT IF endorphins modulate pain, then naloxone should affect pain behaviour even in subjects who have not received exogenous opiates. However, some naloxone studies claim a lack of effect1,2, others a hyperalgesic effect3-5, and others both hyperalgesic and analgesic effects6,7. Such discrepancies may arise from the different methods used to induce and assess pain8, and from variation in dose. We know of only one previous human study which used multiple doses of naloxone6; this indicated a dose-dependent bi-directional effect. In the present study, a clinical pain paradigm was used to generate a dose-response curve for naloxone. We report that naloxone produces analgesia at low doses and hyperalgesia at high doses.
Full-textDOI: · Available from: Howard L Fields, Mar 19, 2014
Article: Opioid Antagonists[Show abstract] [Hide abstract]
ABSTRACT: Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available on www.palliativedrugs.com. Country-specific books (Hospice and Palliative Care Formulary USA, and Palliative Care Formulary, British and Canadian editions) are also available and can be ordered from www.palliativedrugs.com. The series editors welcome feedback on the articles (email@example.com).Journal of pain and symptom management 02/2014; 47(2):341-52. DOI:10.1016/j.jpainsymman.2013.12.223 · 2.74 Impact Factor
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ABSTRACT: Background: Inadequate pain control and opioid-related adverse effects result in delayed patient recovery and discharge times. Adjuvants help to improve the quality of analgesia and decrease opioid consumption, consequently decreasing opioid-related effects, such as nausea and vomiting, sedation, ileus, and respiratory depression. We review the mechanisms and clinical evidence for nonopioid adjuvants. Methods: MEDLINE, EMBASE, and the Cochrane Register were searched for meta-analyses, systematic reviews, and randomized, controlled trials that compared the adjuvants ketamine, gabapentin, pregabalin, dexmedetomidine, clonidine, and dexamethasone with placebo. Keywords used in the search included "plastic surgery," "reconstructive surgery," "opioid," "pain," "analgesia," and the names of each adjuvant. The references of included studies were searched for additional relevant studies. Results: Ketamine was found in 6 meta-analyses to have a significant reduction in opioid requirements and may reduce the hyperalgesia associated with opioids. This seems to be most beneficial in surgeries where high postoperative pain is expected. Multiple robust trials have demonstrated that the gabapentinoids and alpha-2 agonists significantly improve quality of analgesia and decrease opioid consumption. Two recent meta-analyses found that a single low-dose of dexamethasone used for postoperative nausea and vomiting prophylaxis may also improve postoperative analgesia. There is also emerging evidence for the use of low-dose naloxone, adenosine, and neuraxial neostigmine and acupuncture as part of a successful multimodal pain management regimen. Conclusions: Although there is a lack of studies specifically focused in the plastic and reconstructive surgery patient population, the existing literature provides information about when the above adjuvants are likely to have the greatest impact.Plastic & Reconstructive Surgery 10/2014; 134(4S-2 Current Concepts in Pain Management in Plastic Surgery):69S-82S. DOI:10.1097/PRS.0000000000000703 · 3.33 Impact Factor