Mixing Meds Causes Clogs-Tuesday Tube Facts Apr 2, 2021 Did you know…? Mixing medication with formula may result in clogging. One study found that of 24 incompatible drug-formula mixtures, 23 (96%) resulted in tube obstruction. Read the Full Story References: Boullata, J. Drug Administration Through an Enteral Feeding Tube: The rationale behind the guidelines. The American Journal of Nursing. 2009. 109(10), 34-43.