Naloxone dose dependently produces analgesia and hyperalgesia in postoperative pain.

Nature (Impact Factor: 42.35). 05/1979; 278(5706):740-1. DOI: 10.1038/278740a0
Source: PubMed

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.


Available from: Howard L Fields, Mar 19, 2014
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