Netzer P, Sendensky A, Wissmeyer MP et al.
University Hospital Bern, Bern, Switzerland.
Aliment Pharmacol Ther 2008;28:1334–41.
Editor’s note: This article reports the effects of naloxone-3-glucuronide (NX3G), a non-absorbable opiate antagonist, on morphine-induced constipation. The study used a placebo-controlled, randomized, three-way crossover design, and included 15 male volunteers aged 20–26 years who each served as their own control. NX3G was obtained from a commercial source and manually packaged in gelatine capsules that are resistant to gastric acid. The three treatment regimens were placebo + placebo, morphine + placebo, and morphine + NX3G. There was a washout period of at least 14 days between medications. Oral NX3G and oral placebo were each administered at the start of the study and then every 4 h for 24 h, while subcutaneous morphine and subcutaneous placebo were each delivered 2 h after study onset and then every 6 h for 24 h. Indium-111-labeled Amberlite resin was administered at the start of the study to allow for scintigraphic estimation of the colonic transit time (CTT).