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diltiazem vs theophylline

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

major Known Drug Interaction

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Recommendation: Your doctor may need to lower your theophylline dose while you are taking diltiazem. Watch for signs of too much medicine, such as nausea, tremors, or a fast heartbeat.

Drug Class
diltiazem Calcium Channel Blocker
theophylline Methylxanthine Bronchodilator
Type
diltiazem Prescription
theophylline 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.

theophylline

Theophylline is a medicine that helps you breathe easier. It treats the symptoms of asthma and other lung problems.

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.

theophylline

Theophylline treats the symptoms of long-term asthma and other lung diseases. These include emphysema and chronic bronchitis, which make it hard to breathe. This medicine helps to open up your airways so you can breathe easier.

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.

theophylline

Theophylline is a bronchodilator. It works by relaxing the muscles in your airways. This allows more air to flow in and out of your lungs.

Common Side Effects
diltiazem
  • Swelling in your ankles or feet
  • Headache
  • Dizziness
  • Slow heart rate
  • Constipation
theophylline
  • Nausea
  • Vomiting
  • Headache
  • Trouble sleeping (insomnia)
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
theophylline
  • Difficulty breathing 2,273
  • Asthma 1,942
  • Pneumonia 1,317
  • Wheezing 1,306
  • Vomiting 1,101
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.

theophylline

If your theophylline levels get too high in your blood, it can cause serious side effects. These include severe vomiting, irregular heartbeats, and seizures. These can be life-threatening.

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.

theophylline

It is not known if theophylline can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if theophylline passes into breast milk, so talk to your doctor if you are breastfeeding.

Also Compare, Nearby Drugs

How to Read This diltiazem vs theophylline Comparison

diltiazem is classified in the Calcium Channel Blocker drug class, while theophylline sits within the Methylxanthine Bronchodilator 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 theophylline has 7,939. 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 major interaction flagged in FDA labeling, attributed to diltiazem can slow down the liver's ability to break down theophylline. this can cause the medicine to build up in your body and reach toxic levels.. 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 theophylline - 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.