Medication absorption considerations in patients with postpyloric enteral feeding tubes

The gastrointestinal absorption sites of medications administered via postpyloric enteral feeding tubes were examined.

Many issues must be considered when administering medications via the postpyloric route, including interactions with enteral feeds, additional toxicities, and the concern of whether the medication will be absorbed. Despite the potential clinical significance of this information, data regarding the gastrointestinal site of absorption for most medications are lacking. Gastrointestinal absorption sites for all drugs for which requests for information on absorption sites were received at our institution since 2008 (n = 124) were evaluated by reviewing the package insert, consulting tertiary references, conducting primary literature searches, or contacting the drug manufacturer. Seventy (56.5%) of the 124 drugs reviewed had information available regarding the site of absorption. Just 2 drugs required acid for absorption and thus should be administered only through the stomach, while 2 other drugs were found to bind extensively to tubing and should not be administered in this manner. For 3 drugs, increased absorption may occur when they are administered directly into the small bowel. Seven medications had decreased absorption when administered directly to the small bowel, and 10 drugs were clearly not absorbed when administered through either the duodenal or the jejunal route.

The implications of absorption site should be considered for all patients receiving medications via postpyloric feeding tubes. Several medications cannot be administered through alternative routes because gastric acid is needed for their absorption, the medications may bind to the tubing, or drug absorption is altered at the intestinal site.