Modification of Fentanyl Analgesia by Antidepressants

Abstract

Clinical practice often requires simultaneous administration of antidepressants with opioids (oncology, rheumatology). Coadministration may either attenuate or potentiate opioid analgesia. The purpose of this paper was to verify how the analgesic action of fentanyl (0.05 mg/kg) is affected by single administration as well as 4- or 21-day premedication with antidepressants characterized by various mechanisms of action. The effects of amitriptyline 3 mg/kg, moclobemide 5 mg/kg, fluoxetine 5 mg/kg and reboxetine 0.08 mg/kg were investigated. Experiments were conducted on normotensive Wistar Kyoto rats. The pain threshold was measured using an analgesimeter. It was concluded that the single administration of an antidepressant increases the analgesic action of fentanyl. Four-day premedication with fluoxetine and reboxetine significantly attenuated the antinociceptive action of fentanyl, whereas 21-day premedication with all antidepressants investigated (fluoxetine, amitriptyline, moclobemide, reboxetine) markedly decreased it. The potential clinical importance of this observation is discussed.

Mechanisms of morphine–venlafaxine interactions in diabetic neuropathic pain model

“…Our previous observations and the works by other authors showed that potential changes in co-analgesic action should be visible within 3 weeks of administration. Type of repeated treatment used in this study resembles the co-analgetic use of antidepressants in clinical practice and the same model of drug administration was used in previous publications [15][16][17].…”

“…The nociceptive thresholds in this part were determined on day 19 (acute VFX) or on day 39 (repeated VFX) of study, 30 min before VFX/MRF administration (baseline value) and at 30, 60, 90, 120, 150 and 180 min after morphine-venlafaxine injection. Timing of thresholds measurements was taken from earlier an work by Juś et al [17]. For controls, baseline thresholds values were determined 30 min before administration of (controls 1 and 3) 0.9% NaCl with 0.5% MC and (control 2) MRF in 0.9% NaCl + 0.5% MC; next measurements were conducted at the abovementioned time points.…”

“…), 30 min before VFX/MRF administration (baseline value determination in NLX, YOH and PCA experiment, as well as in control group No. 2), and next at 30, 60, 90, 120, 150 and 180 min after morphine-venlafaxine injection (timing from a paper by Juś et al [17]). For control groups (1) and (4), baseline values of nociceptive thresholds were determined 30 min before 0.9% NaCl with 0.5% MC.…”

Antidepressant Drugs for Prevention of Acute and Chronic Postsurgical Pain

“…Garrett, 2011 68 Study drug is a combination of amitriptyline, ketoprofen, and oxymetazolin. Juś, 2010 69 Animal study. Krimmer, 1986 70 Not an RCT.…”