Absorptionen af doxycyclin fra mave- tarmkanalen kan blive hæmmet af bi - eller trivalente ioner såsom aluminium, zink, kalcium (som blandt andet findes i mælk, mælkeprodukter og kalciumholdige frugtsafter), af magnesium (som findes i f. eks. anticider) eller af jernpræparater, aktivt kul, kolestyramin, bismuth- chelater og sukralfat.
The absorption of doxycycline from the gastro-intestinal tract may be inhibited by bi- or tri-valent ions such as aluminium, zinc, calcium (found for example in milk, dairy products and calcium- containing fruit juices), by magnesium (found for example in antacids) or by iron preparations, activated charcoal, cholestyramine, bismuth chelates and sucralfate.