diltiazem vs flecainide
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Side-by-side comparison of diltiazem and flecainide. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
There has been too little experience with the coadministration of flecainide acetate with nifedipine or diltiazem to recommend concomitant use.
Cardizem, Tiazac
Tambocor
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.
Flecainide is a medicine used to prevent irregular heartbeats. It helps your heart beat normally.
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.
This medicine can prevent fast heart rates in the upper chambers of the heart. This includes supraventricular tachycardia and atrial fibrillation/flutter. Flecainide can also prevent life-threatening fast heartbeats in the lower chambers (ventricles). It is usually started in the hospital for these serious ventricular problems.
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.
Flecainide works by slowing down electrical signals in the heart. This helps to stabilize your heart rhythm. It belongs to a class of drugs called Class IC antiarrhythmics.
- • Swelling in your ankles or feet
- • Headache
- • Dizziness
- • Slow heart rate
- • Constipation
- • Dizziness
- • Vision problems
- • Difficulty breathing
- • Headache
- • Nausea
- Dyspnoea 3,202
- Fatigue 2,638
- Nausea 2,372
- Pain 2,365
- Dizziness 2,091
- Irregular heartbeat in the upper chambers 337
- Feeling tired 276
- Difficulty breathing 270
- Feeling lightheaded 255
- Feeling sick to your stomach 244
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.
Flecainide can increase the risk of death or cardiac arrest in some patients who have had a heart attack. It is generally not recommended for people with less serious, but unpleasant, heart rhythm problems. Flecainide is also not recommended if you have chronic atrial fibrillation.
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.
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if flecainide can harm an unborn baby. Talk to your doctor about the risks and benefits of taking flecainide while breastfeeding.
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How to Read This diltiazem vs flecainide Comparison
diltiazem is classified in the Calcium Channel Blocker drug class, while flecainide sits within the Class IC Antiarrhythmic 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 12,668 submissions while flecainide has 1,382. 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 minor interaction flagged in FDA labeling, attributed to there is not enough medical information available to know how these two drugs interact when used together.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for diltiazem or flecainide.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.