amlodipine vs diltiazem
Side-by-side comparison of amlodipine and diltiazem Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Norvasc
Cardizem, Tiazac
Amlodipine (Norvasc) is a drug that lowers blood pressure and treats chest pain. It belongs to a class of drugs called calcium channel blockers.
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.
This medicine treats high blood pressure (hypertension). Lowering blood pressure reduces the risk of strokes and heart attacks. Amlodipine also treats chest pain (angina) caused by coronary artery disease, including chronic stable angina and vasospastic angina.
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.
Amlodipine blocks calcium from entering heart and blood vessel cells. This relaxes and widens blood vessels, making it easier for blood to flow. As a result, the heart does not have to work as hard, which lowers blood pressure and reduces chest pain.
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.
- • Swelling in your ankles or feet
- • Dizziness
- • Flushing (redness of the face)
- • Palpitations (feeling your heart beat rapidly or irregularly)
- • Fatigue (feeling tired)
- • Swelling in your ankles or feet
- • Headache
- • Dizziness
- • Slow heart rate
- • Constipation
- Feeling tired 15,696
- Diarrhea 14,038
- Feeling sick to your stomach 13,425
- Shortness of breath 13,222
- Medication not working 12,075
- Shortness of breath 3,200
- Tiredness 2,637
- Feeling sick to your stomach 2,372
- Discomfort 2,364
- Feeling lightheaded 2,089
Amlodipine may cause low blood pressure, especially if you have severe aortic stenosis. Some people with severe heart disease may experience worsening chest pain or a heart attack when starting or increasing the dose of amlodipine. If you have severe liver problems, your doctor will increase your dose slowly.
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.
Tell your doctor if you are pregnant or plan to become pregnant. High blood pressure during pregnancy can harm both the mother and the baby. Amlodipine passes into breast milk, but no harmful effects on the breastfed infant have been seen.
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.
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How to Read This amlodipine vs diltiazem Comparison
amlodipine is classified in the Calcium Channel Blocker drug class, while diltiazem sits within the Calcium Channel Blocker class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. 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, amlodipine has 68,456 submissions while diltiazem has 12,662. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. 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 amlodipine and diltiazem — 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.