Antinociceptive and adverse effects of morphine:ketamine mixtures in rats.

Autor: Strumberger CD; Department of Psychological Science, Creighton University, Omaha, Nebraska, USA., D'Epagnier EJ, Nguyen KH, Rogers JD, Meyer MP, Malhotra Y, Hinman JE, Jansen EL, Minervini V
Jazyk: angličtina
Zdroj: Behavioural pharmacology [Behav Pharmacol] 2024 Apr 01; Vol. 35 (2-3), pp. 122-131. Date of Electronic Publication: 2023 Nov 15.
DOI: 10.1097/FBP.0000000000000761
Abstrakt: Prescription opioids are the gold standard for treating moderate to severe pain despite their well-documented adverse effects. Of all prescription medications, opioids are abused most widely, and fatal overdoses have reached epidemic levels. One strategy for improving the margin of safety of opioids is combining them with non-opioid drugs to decrease the opioid dose needed for pain relief, thereby reducing adverse effects that occur with larger doses. The N-methyl-D-aspartate receptor antagonist ketamine has been used safely as an analgesic but only under a very limited range of conditions. The current studies characterized the antinociceptive, behavioral suppressant, and gastrointestinal effects of morphine and ketamine alone and in mixtures to determine their interaction in 24 adult male Sprague-Dawley rats (n = 8 per assay). Given alone, both morphine and ketamine produced antinociception, decreased responding for food, and reduced gastrointestinal transit (i.e. produced constipation). The effects of morphine:ketamine mixtures generally were additive, except for the antinociceptive effects of 1:1 mixtures for which the difference in slope (i.e. non-parallel shift) between the observed and predicted effects suggested synergy at smaller doses and additivity at larger doses. The potency of morphine to produce constipation was not enhanced by administration of morphine:ketamine mixtures with antinociceptive effects. The nature of the interaction between morphine and ketamine for adverse effects such as dependence, withdrawal, abuse, or respiratory depression remains unknown but also might be related to the ratio of each drug in mixtures. It will be important to identify conditions that produce the largest potential therapeutic window in humans.
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Databáze: MEDLINE