Will the medicine interact directly with the enteral feed?

It is important to check this with the manufacturer for all medicines (including those medicines labelled 'take before food'), as such interactions may alter the bioavailability of the drug, cause degradation and/or inactivation of either the drug or feed, or influence drug clearance.

For example, incompatibilities between drugs such as carbamazepine, warfarin and phenytoin and enteral feeds will affect drug absorption, and interaction between antacids and acidic solutions such as promethazine and enteral feeds will cause coagulation in the tube, increasing the risk of tube blockage. In addition, some drugs, such as penicillins and tetracycline, may require administration on an empty stomach.