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diltiazem vs rifampin

Side-by-side comparison of diltiazem and rifampin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

moderate Known Drug Interaction

Rifampin : Coadministration of rifampin with diltiazem lowered the diltiazem plasma concentrations to undetectable levels. Avoid coadministration of diltiazem with rifampin or any known CYP3A4 inducer.

Recommendation: You should avoid taking these two medications together.

Drug Class
diltiazem Calcium Channel Blocker
rifampin Rifamycin Antibiotic
Type
diltiazem Prescription
rifampin Prescription
Summary
diltiazem

Diltiazem is a medicine that helps lower high blood pressure and prevent chest pain. It belongs to a class of drugs called calcium channel blockers.

rifampin

Rifampin is an antibiotic medicine. It fights bacteria in your body to treat infections.

What It Treats
diltiazem

Diltiazem is used to treat high blood pressure. It can be used alone or with other blood pressure medicines. Diltiazem also helps manage chronic stable angina (chest pain) and angina caused by spasms in the heart's blood vessels.

rifampin

Rifampin treats tuberculosis (TB) and helps eliminate the bacteria that cause meningitis from your nose and throat. It is important to use rifampin only for infections that are proven or strongly suspected to be caused by bacteria. This helps to prevent bacteria from becoming resistant to the medicine.

How It Works
diltiazem

Diltiazem works by relaxing blood vessels, which lowers blood pressure. It also reduces the heart's workload, which can prevent chest pain. This medicine blocks calcium from entering heart and blood vessel cells.

rifampin

Rifampin works by stopping bacteria from growing and multiplying. It does this by blocking a key enzyme that the bacteria need to make proteins. This helps your body fight off the infection.

Common Side Effects
diltiazem
  • Swelling in your ankles or feet
  • Headache
  • Dizziness
  • Slow heart rate
  • Constipation
rifampin
  • Heartburn
  • Upset stomach
  • Loss of appetite
  • Nausea
  • Vomiting
FAERS Reports
diltiazem
  • Shortness of breath 3,200
  • Tiredness 2,637
  • Feeling sick to your stomach 2,372
  • Discomfort 2,364
  • Feeling lightheaded 2,089
rifampin
  • Drug Interaction 970
  • Drug Reaction With Eosinophilia And Systemic Symptoms 727
  • Nausea 628
  • Condition Aggravated 550
  • Pyrexia 541
Serious Warnings
diltiazem

Diltiazem can interact with other heart medications. Tell your doctor if you take beta-blockers or digoxin. Using diltiazem with these drugs can cause heart problems. Your doctor may need to adjust your dosages.

rifampin

Rifampin can cause liver problems. Tell your doctor right away if you have yellowing of the skin or eyes, dark urine, or stomach pain. Rifampin can also cause blood problems. Tell your doctor if you have unusual bleeding or bruising.

Pregnancy
diltiazem

Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. It is not known if diltiazem will harm your unborn baby. Diltiazem passes into breast milk, so talk to your doctor about breastfeeding while taking this medicine.

rifampin

Tell your doctor if you are pregnant or plan to become pregnant. Rifampin can make birth control pills less effective, so use other forms of birth control. Talk to your doctor if you are breastfeeding.

Also Compare, Nearby Drugs

How to Read This diltiazem vs rifampin Comparison

diltiazem is classified in the Calcium Channel Blocker drug class, while rifampin sits within the Rifamycin Antibiotic class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, diltiazem has 12,662 submissions while rifampin has 3,416. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known moderate interaction flagged in FDA labeling, attributed to rifampin speeds up how quickly your body breaks down diltiazem, which can cause the diltiazem to disappear from your blood and stop working.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between diltiazem and rifampin - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.