Administration Of Loperamide Research Articles

Stimulation of gastrointestinal motility by loperamide in dogs.

The effects of loperamide on gastrointestinal motility were investigated in conscious fasted dogs chronically fitted with strain-gauge transducers on the antrum, the jejunum, and the colon. Oral administration of loperamide (0.1 mg/kg) induced, after a delay of 20-30 min, a long-lasting (8-12 hr) stimulation of gastrointestinal motility associated with a disorganization of the cyclic activity at the three levels investigated. These effects were reproduced by a subcutaneous administration at the same dose and were antagonized by previous intravenous administration of naloxone or a quaternary opiate antagonist. Intracolonic administration (0.1 mg/kg) stimulated, after a delay of 20-30 min, colonic motility only. Intracerebroventricular loperamide (1 microgram/kg) induced a long-lasting (15-20 hr) inhibition of the gastric motility and a short (2-hr) disorganization of the jejunal motor profile. These data show that oral loperamide stimulates gastrointestinal motility in dogs and involves peripheral opiate receptors.

Effect of loperamide and naloxone on mouth-to-caecum transit time evaluated by lactulose hydrogen breath test.

The effect of loperamide and naloxone on mouth-to-caecum transit time was evaluated by the lactulose hydrogen breath test in four men and four women. Each subject underwent tests during the administration of placebo, loperamide (12-16 mg po), naloxone (40 micrograms/kg/h by a three-hour intravenous infusion), and loperamide plus naloxone, carried out at intervals of one or two weeks. The transit time was significantly longer after loperamide, and this effect was antagonised by the concomitant administration of naloxone whereas naloxone administered alone had no effect on mean transit time. No clinically important side effects were reported.

Abnormalities in gastrointestinal motor activity in patients with short bowels: Effect of a synthetic opiate

We have investigated the fasting and postprandial patterns of gastrointestinal pressure activity in a group of patients with extensive (>100 cm) resections of the distal small bowel. Each short bowel patient was studied on 2 consecutive days with random single blind administration of either loperamide (6 mg at 5 h and at 30 min before the meal) or placebo, and 20 healthy controls were studied on single days (13 basal fasting, 7 placebo). During fasting, the duration of the interdigestive motor complex was significantly shorter in patients with short bowel syndrome (71.1 ± 15.6 min vs. 109 ± 7.8 min for controls, p < 0.03); hence, the frequency of complexes was increased. The duration of phase 2 was strikingly shorter in patients (18.7 ± 7.0 min vs. 52.9 ± 8.5 min for controls, p < 0.03). Gastric emptying and postprandial motor activity were identical in patients and controls. During fasting, loperamide prolonged phase 3 (7.6 ± 2.2 min vs. 4.3 ± 1.1 min for placebo, p < 0.03). Postprandially, loperamide shortened the time from meal ingestion to the first phase 3 by 50% (p < 0.003), and increased motility index and frequency of contraction in the gut (p < 0.01). Thus, gut motor activity in the short bowel syndrome is characterized by more frequent interdigestive motor complexes, marked reduction in phase 2 activity, and a normal feeding pattern. Loperamide therapy increases feeding activity while at the same time shortening its duration.

Inhibition of postprandial pancreatic and biliary secretion by loperamide in patients with short bowel syndrome.

Patients with the short bowel syndrome are usually afflicted by chronic diarrhoea and treated with opiate drugs, yet little documentation of the effects of such drugs on digestive function is available. In the present study we found that acute oral administration of loperamide resulted in 50% inhibition of postprandial trypsin and bilirubin output in patients with short bowel syndrome. These changes are consistent with an opiate effect.

Effects of loperamide on the gastric and intestinal motilities in the guinea pig and dog (author's transl)

In anesthetized dogs, intravenous administration or intrajejunal infusion of Loperamide produced the excitatory effect of gastric, small and large bowel motilities accompanied with elevation of the muscle tone. The excitatory response was slightly suppressed by administration of atropine. Such effects were similar to those of morphine and methadone. In non-anesthetized spinal guinea pigs, Loperamide increased colonic motility accompanied with the augmentation of the colonic muscle tone, but the conduction of the contraction waves was prevented. In anesthetized guinea pigs, intravenous administration of Loperamide reduced the rate of the rhythmic contraction waves of the small intestine, but its effect on the muscle tone was not evident. The activity of Loperamide as an antidiarrheal agent was discussed.