A comparison of the effect of oral controlled release morphine and intramuscular morphine on gastric emptying.

The effect on gastric emptying of the administration of oral controlled-release morphine 20 mg and intramuscular morphine 10 mg is compared. Gastric emptying was estimated by the measurement of paracetamol absorption. Statistically significant differences exist between the two treatments. There is slight inhibition of gastric emptying with the oral preparation and almost complete inhibition with intramuscular morphine.