tetracycline
6 interactions related to tetracycline
doxycycline + iron
Iron forms an insoluble chelate complex with doxycycline in the gastrointestinal tract, dramatically reducing absorption of the antibiotic. Studies show ferrous sulfate co-administration can lower doxycycline serum levels by 80% or more, potentially leading to treatment failure.
tetracycline + zinc
Zinc forms a chelate with tetracycline in the gastrointestinal tract, reducing absorption of the antibiotic by approximately 30 percent. The interaction also reduces zinc absorption.
tetracycline + calcium
Calcium binds tightly to tetracycline in the gut, forming an insoluble chelate that cannot be absorbed. Dairy products and calcium supplements can reduce tetracycline absorption by 50 to 90 percent, often dropping serum levels below the threshold needed to treat infection.
yogurt + antibiotics
Yogurt's calcium content can reduce the absorption of tetracycline and fluoroquinolone antibiotics through chelation, and antibiotics may also kill the live probiotic bacteria in yogurt. Taking yogurt and antibiotics simultaneously reduces the effectiveness of both.
doxycycline + calcium
Calcium chelates doxycycline in the gut, forming an insoluble complex that cannot be absorbed. Co-administration with calcium supplements or dairy products can reduce doxycycline absorption by 50 to 80 percent.
doxycycline + magnesium
Magnesium ions chelate doxycycline in the gastrointestinal tract, forming an insoluble complex that markedly reduces antibiotic absorption. Magnesium-containing antacids and supplements can lower doxycycline bioavailability by up to 90 percent.