Study objective: This study was conducted to determine whether gastric lavage reduces the absorption of ingested liquids.
Methods: The study design was a randomized controlled human volunteer crossover study in 10 subjects. On 2 separate occasions 2 weeks apart, the volunteers ingested a solution of 4.0 g of acetaminophen in 60 mL of water. Eight blood specimens were obtained over the initial 8 hours for determination of serum acetaminophen concentrations, which were used to calculate routine pharmacokinetic parameters. One hour after 1 drug ingestion, gastric lavage was performed through a 34-F orogastric tube. Serum acetaminophen concentrations were measured by high-performance liquid chromatography and a 2-tailed t test was used for statistical analysis.
Results: The mean values for area under the concentration curve (+/-SD) for the control and gastric lavage groups were 195+/-31 and 154+/-52 mg/L.hour, respectively (P <.05). The mean reduction in acetaminophen bioavailability because of gastric lavage was 20%+/-28% (95% confidence interval 3 to 37).
Conclusion: In this experimental model for the ingestion of liquids, gastric lavage at 1 hour resulted in a significant decrease in the mean serum bioavailability of acetaminophen. Nonetheless, this treatment effect is unlikely to be of clinical value because of its modest extent, unreliable performance, and the availability of a more effective, less risky alternative, activated charcoal.