The effect of morbid obesity on morphine glucuronidation - Archive ouverte HAL Access content directly
Journal Articles Pharmacological Research Year : 2017

The effect of morbid obesity on morphine glucuronidation

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The purpose of the present work was to study the change in morphine metabolic ratio in obese subjects before and after Roux-en-Y Gastric Bypass (RYGB) and to identify clinical and/or biological factors associated with this change. The pharmacokinetics (PK) of oral morphine (30mg), morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) was performed in patients before (n=25; mean BMI=43.2 (35.4-61.9)kg/m2), 7-15days (n=16) and 6 months after RYGB (n=19; mean BMI=32.3 (25.4-46.0)kg/m2). Morphine Cmax and AUC0-inf were significantly increased and morphine Tmax significantly shortened at 6 months after RYGB compared with preoperative data, indicating an important increase in the rate and extent of morphine absorption. The morphine metabolic ratio 0-inf M3G+M6G/Morphine, decreased significantly from the preoperative to 6 months postoperative period with an average of -26% (range -74%; +21%; p=0.004), but not in the immediate post-operative period. The change in morphine metabolic ratio was associated with a change in BMI, fat mass in kg, and triglyceride levels (rho=0.5, p≤0.04). The degree of change in several markers of low-grade inflammation, or the level of liver steatosis and fibrosis before surgery, was not associated with the change in morphine metabolic ratios. Our findings indicate that RYGB-induced weight loss significantly decreases morphine metabolic ratio, arguing for an effect of morbid obesity on glucuronidation. With glucuronide exposure at 6 months similar to preoperative values, a higher morphine AUC0-inf should encourage reducing morphine dosage in patients undergoing RYGB and chronically receiving immediate-release oral morphine.
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Dates and versions

inserm-03822989 , version 1 (20-10-2022)



Celia Lloret-Linares, Huilong Luo, Alexandra Rouquette, Laurence Labat, Christine Poitou, et al.. The effect of morbid obesity on morphine glucuronidation. Pharmacological Research, 2017, 118, pp.64-70. ⟨10.1016/j.phrs.2016.08.031⟩. ⟨inserm-03822989⟩
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