ranitidine vs theophylline

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Side-by-side comparison of ranitidine 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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Drug Class
ranitidine H2 Receptor Antagonist
theophylline Methylxanthine Bronchodilator
Type
ranitidine Over-the-Counter
theophylline Prescription
Summary
ranitidine

Ranitidine (Zantac) helps reduce stomach acid. It can relieve heartburn and sour stomach.

theophylline

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

What It Treats
ranitidine

This medicine treats heartburn caused by acid indigestion and sour stomach. You can also take it to prevent heartburn. It can prevent heartburn caused by eating or drinking certain foods and drinks.

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
ranitidine

Ranitidine is an H2 receptor antagonist. It works by blocking histamine. Blocking histamine reduces the amount of acid your stomach makes.

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
ranitidine
  • Headache
theophylline
  • Nausea
  • Vomiting
  • Headache
  • Trouble sleeping (insomnia)
FAERS Reports
ranitidine
  • Breast Cancer 24,853
  • Prostate Cancer 22,252
  • Colorectal Cancer 17,674
  • Bladder Cancer 16,746
  • Renal Cancer 16,278
theophylline
  • Dyspnoea 2,273
  • Asthma 1,942
  • Pneumonia 1,318
  • Wheezing 1,306
  • Vomiting 1,101
Serious Warnings
ranitidine

No specific warnings noted.

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
ranitidine

No pregnancy information available.

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 ranitidine vs theophylline Comparison

ranitidine is classified in the H2 Receptor Antagonist 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 split between OTC and prescription status, which affects access and supervision.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, ranitidine has 97,803 submissions while theophylline has 7,940. 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 ranitidine can slow down how quickly your liver processes theophylline, which may cause the drug to build up to unsafe levels in your body.. 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 ranitidine or theophylline.

Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.