MAJOR — Use With Caution
FDA-documented interaction. Diltiazem may become completely ineffective. Alternative antihypertensive needed during rifampin treatment.
Evidence level: STRONG
Rifampin can reduce diltiazem levels by up to 95%, essentially making it stop working. Your blood pressure and heart rate control could be completely lost.
Rifampin induces CYP3A4, dramatically reducing diltiazem levels (up to 95% reduction reported). Diltiazem may become completely ineffective. FDA labels warn.
Your blood pressure and heart medication will likely not work while taking rifampin. Your doctor needs to switch to an alternative that is not affected (beta-blocker, ACE inhibitor).
Follow each medication's specific timing instructions. Rifampin — check if it requires an empty stomach or should be taken with food. Diltiazem follows its normal schedule. Complete the full antibiotic course as prescribed.
Higher risk for: those with liver or renal impairment, elderly, concurrent use of nephrotoxic or hepatotoxic drugs, history of C. difficile infection, or those on narrow therapeutic index medications (warfarin, digoxin).
Elevated blood pressure, rapid heart rate, chest pain, angina symptoms
Switch to antihypertensive not dependent on CYP3A4 (beta-blocker, ACE inhibitor, ARB). Monitor blood pressure and heart rate closely.
Antibiotic interactions are often temporary (duration of treatment). Space supplements and probiotics 2-3 hours away from antibiotic doses. Ask your pharmacist if timing adjustments can reduce the interaction risk.
Rifampin can reduce diltiazem levels by up to 95%, essentially making it stop working. Your blood pressure and heart rate control could be completely lost.
Follow each medication's specific timing instructions. Rifampin — check if it requires an empty stomach or should be taken with food. Diltiazem follows its normal schedule. Complete the full antibiotic course as prescribed.
Elevated blood pressure, rapid heart rate, chest pain, angina symptoms
Antibiotic interactions are often temporary (duration of treatment). Space supplements and probiotics 2-3 hours away from antibiotic doses. Ask your pharmacist if timing adjustments can reduce the interaction risk.
Switch to antihypertensive not dependent on CYP3A4 (beta-blocker, ACE inhibitor, ARB). Monitor blood pressure and heart rate closely.
Or browse the full interaction database (121,000+ pairs).