Gastrointestinal transit following intrathecal or subcutaneous narcotic analgesics

This paper reports investigations on the effects on gastrointestinal transit of subcutaneous or intrathecal administration of opiates: morphine, sufentanil and alfentanil. Subcutaneous administration of opiates produced a significant dose-dependent decrease in transit of a charcoal meal test. Intrathecal administration of morphine to Wistar rats with catheter chronically implanted in the subarachnoid space did not cause a decrease in gastrointestinal transit. However, in freshly prepared rats with intrathecal catheter in the subarachnoid space, morphine significantly decreased intestinal transit of charcoal meal. In addition, sufentanil and alfentanil, on intrathecal administration in rats with chronically implanted catheters, caused a marked dose-dependent slowing of the passage of meal. Prior s.c. administration of the opiate antagonist naloxone completely blocked the depression of gastrointestinal transit caused by high doses of intrathecal sufentanil and s.c. administered morphine.