Bioavailability of medication delivered via nasogastric tube is decreased in the immediate postoperative period

Background A study was performed to determine bioavailability of medication delivered via nasogastric tube in patients after abdominal surgery. Methods Acetaminophen (20 mg/kg) was administered to each patient per os at least 48 hours prior to abdominal surgery and via nasogastric tube 3 hours postoperatively. The nasogastric tube was clamped for 30 minutes after drug administration, prior to resuming suction. Serum levels of acetaminophen were measured 0, 40, and 90 minutes after each dose. Results Acetaminophen levels were significantly lower (P<0.001) when the drug was administered via nasogastric tube postoperatively. Conclusions Decreased bioavailability of medications delivered via nasogastric tube may have important clinical implications and should be taken into consideration during the postoperative period.