antibiotic
12 interactions related to antibiotic
clarithromycin + red yeast rice
Clarithromycin is a strong CYP3A4 inhibitor. Red yeast rice's active compound, monacolin K, is chemically identical to the statin lovastatin and is cleared mainly by CYP3A4. Combining them slows clearance of the statin-like compound and raises its blood levels, increasing the risk of muscle injury and, rarely, rhabdomyolysis.
doxycycline + iron
Iron forms an insoluble chelate complex with doxycycline in the gut, sharply reducing absorption of the antibiotic. In controlled human studies, ferrous sulfate taken together with doxycycline cut serum antibiotic levels substantially, which can undermine treatment.
doxycycline + magnesium
Magnesium ions can bind doxycycline in the gastrointestinal tract, forming a poorly absorbed complex that reduces how much antibiotic reaches the bloodstream. Magnesium-containing supplements, antacids, and laxatives can meaningfully lower doxycycline absorption if taken at the same time.
doxycycline + calcium
Calcium binds doxycycline in the gut, forming a complex the body cannot fully absorb. Taking doxycycline together with calcium supplements, calcium-based antacids, or large dairy servings can lower how much antibiotic reaches the bloodstream, though doxycycline binds calcium less than older tetracyclines.
metronidazole + alcohol
Metronidazole is traditionally said to cause a disulfiram-like reaction with alcohol — flushing, nausea, and headache. Controlled human studies have not reproduced a true disulfiram reaction, so the effect appears real but uncommon and usually mild. Most product labels still advise avoiding alcohol during treatment and for a short period afterward as a precaution.
tetracycline + zinc
Zinc forms a chelate with tetracycline in the gastrointestinal tract, modestly reducing absorption of the antibiotic. The interaction also reduces zinc absorption. Doxycycline is much less affected.
tetracycline + calcium
Calcium binds to tetracycline in the gut, forming an insoluble chelate that the intestine cannot absorb. Dairy products, calcium supplements, and calcium-based antacids can sharply reduce how much tetracycline reaches your bloodstream, which can drop levels below what is needed to treat the infection.
caffeine + ciprofloxacin
Ciprofloxacin inhibits the liver enzyme CYP1A2, which is the main pathway that clears caffeine. As a result, caffeine is broken down more slowly, its blood levels stay higher for longer, and its stimulant effects are amplified and prolonged while you are on the antibiotic.
aged cheese + linezolid
Linezolid is a reversible, non-selective monoamine oxidase (MAO) inhibitor. Eating tyramine-rich foods such as aged cheese while on linezolid can cause a sudden, dangerous rise in blood pressure (hypertensive reaction).
levofloxacin + calcium
Calcium binds (chelates) levofloxacin in the gastrointestinal tract, modestly lowering the antibiotic's peak blood level. Total drug exposure over the dosing interval is largely preserved, so the effect is smaller than with iron, magnesium, or aluminum. Separating the doses by a couple of hours avoids the interaction.
dairy + fluoroquinolones
Calcium and other metal ions in dairy products bind oral fluoroquinolone antibiotics in the gut, forming poorly absorbed chelate complexes that lower the amount of antibiotic reaching the bloodstream.
coffee + ciprofloxacin
Ciprofloxacin inhibits CYP1A2, the liver enzyme that clears caffeine, slowing caffeine metabolism so a normal amount of coffee produces higher, longer-lasting caffeine levels and stronger stimulant effects.