Anesthesiology
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Clinically, epidural coadministration of opioids and local anesthetics has provided excellent analgesia for various types of pain. However, information about the interaction of these drugs when administered epidurally is limited. Therefore, we evaluated the antinociceptive interaction between morphine and lidocaine on both somatic and visceral noxious stimuli in the rat. ⋯ These data demonstrate that epidurally coadministered morphine and lidocaine produce synergistic analgesia and prolong the duration of analgesia in tests of somatic and of visceral nociception.
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Randomized Controlled Trial Clinical Trial
The interactions of midazolam and flumazenil on human memory and cognition.
Previous research has been unable to show unequivocally whether flumazenil can reverse completely, partially, or not at all the memory effects of benzodiazepines. The effects of midazolam on implicit memory are also unknown. The behavioral effects of flumazenil by itself, and the acute reversal of benzodiazepine effects, are also controversial. The current study was designed to investigate these questions. ⋯ Midazolam impairs explicit and implicit memory. Flumazenil reverses both the sedative and memory effects of the drug. Flumazenil, in the doses used, has no intrinsic actions.
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Randomized Controlled Trial Clinical Trial
Naloxone, meperidine, and shivering.
Meperidine, which binds both mu and kappa opioid receptors, is reportedly more effective in treating shivering than are equianalgesic doses of morphine (a nearly pure mu-receptor agonist). Furthermore, butorphanol, a kappa-receptor agonist/antagonist, treats shivering better than does fentanyl, which mostly binds mu receptors. These data indicate that much of meperidine's special antishivering activity may be mediated by its kappa activity. Accordingly, the authors tested the hypothesis that the antishivering activity of meperidine will be minimally impaired by low-dose naloxone (blocking most mu-receptors), but largely prevented by high-dose naloxone (blocking all mu and most kappa receptors). ⋯ These data indicate that the antishivering property of meperidine is not fully mediated by mu-receptors. Although meperidine has well-known nonopioid actions, stimulation of kappa receptors seems a likely alternative explanation for much of the drug's antishivering action.