Effect of clonidine on gastric emptying of liquids

Abstract

We have investigated the effects of clonidine on gastric emptying of liquids in 30 patients. In a double-blind, randomized design, clonidine 150 micrograms, morphine 10 mg or saline in 1 ml was given i.m. One hour later, the patient drank a paracetamol solution (1.5 g in 50 ml water). Venous blood samples were obtained every 15 min for 90 min thereafter. Plasma paracetamol concentrations were measured using high-pressure liquid chromatography and the area under the concentration-time curve was calculated. The degree of sedation and complications were recorded. The area under the curve for 0-60 min was significantly smaller in the morphine group than in the saline group (P = 0.002; 95% confidence interval (CI) for difference -1237 to -502 micrograms min ml-1), whereas it was greater in the clonidine group compared with the saline group, although this was not significant (95% CI for difference -423 to 1264 micrograms min ml-1). Arterial pressure was significantly lower in the clonidine group compared with the saline group. Both clonidine and morphine appeared to cause mild sedation. We conclude that clonidine 150 micrograms i.m. does not delay gastric emptying of liquids in a similar manner to morphine.

Effects of clonidine and sumatriptan on postprandial gastric volume response, antral contraction waves and emptying: an MRI study

“…The latter effect is likely mediated by the higher AD pressure gradient observed on high resolution manometry. These results provide a mechanistic explanation for reports that clonidine accelerates liquid emptying in healthy subjects and diabetic patients 15,36,37 . Specifically, this study suggests that the acceleration of liquid emptying by α 2 ‐adrenergic agonists observed previously is due not only to the effects on gastric tone, but also to reduced gastric secretion volume.…”

Comparison of the effects of clonidine, loperamide and metoclopramide in two models of gastric emptying in the rat

“…In the dog, clonidine was shown to dose-dependently decrease acetaminophen plasma levels, suggesting a delayed GE [32]. In contrast, and as observed in our study, higher plasma acetaminophen concentrations have been observed in some patients treated with clonidine as compared with the control saline group [33]. Although the rate of acetaminophen absorption is considered as a marker of GE, other factors may affect plasma acetaminophen concentrations, such as possible interference of clonidine with acetaminophen elimination or increases in liquid absorption [32].…”

The Effect of Sedation on Gastric Emptying of a Liquid Marker in Ponies

“…AP has been widely studied as a marker of gastric emptying, and is regarded as being effective and reliable 12,14,15 . Nevertheless, there are concerns that factors other than the gastric emptying rate may influence acetaminophen absorption 16 . Alpha 2 agonists, 17 increased absorption of fluid and electrolytes in the isolated ileum and colon in vitro; and opioids increased fluid absorption from the jejunum in anesthetized rats 18 .…”

“…Alpha 2 agonists, 17 increased absorption of fluid and electrolytes in the isolated ileum and colon in vitro; and opioids increased fluid absorption from the jejunum in anesthetized rats 18 . However, it is uncertain whether drugs in these categories influence small intestinal absorption in the intact animal 16 . Another factor to consider is the influence of drug treatment on the metabolism of acetaminophen.…”