INTERFERENCE OF ORAL PHENYTOIN ABSORPTION BY CONTINUOUS NASOGASTRIC FEEDINGS

Inhibition of phenytoin [an anticonvulsant] absorption by continuous nasogastric tubes feeding was studied in 20 neurosurgery patients and 5 normal subjects. Ten patients receiving phenytoin suspension 300 mg/day coadministered with continuous nasogastric feedings had a mean phenytoin serum concentration of 2.59 .mu.gml. When the feedings were discontinued, the average concentration rose to 10.22 .mu.g/ml in 7 days. In 10 other patients stabilized on phenytoin suspension 300 mg/day, the average serum concentration decreased from 9.80 to 2.72 .mu.g/ml in 7 days when continuous tube feedings were started. Five normal subjects received a single oral dose of phenytoin suspension alone and while drinking a nasogastric tube feeding prepation orally at a rate of 100 ml/h, phenytoin serum levels decreased an average of 71.6% when the tube feeding was taken concurrently.