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allopurinol vs theophylline

Side-by-side comparison of allopurinol and theophylline. 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

Theophylline Clinical Impact Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline. Intervention Monitor and adjust theophylline doses as reflected in the prescribing information.

Recommendation: Your doctor should monitor your theophylline levels and adjust your dose as needed.

Drug Class
allopurinol Xanthine Oxidase Inhibitor
theophylline Methylxanthine Bronchodilator
Type
allopurinol Prescription
theophylline Prescription
Summary
allopurinol

Allopurinol is a medicine that lowers uric acid levels in your body. It helps prevent gout attacks and other problems caused by high uric acid.

theophylline

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

What It Treats
allopurinol

This medicine is used to manage gout in adults. Gout causes painful attacks, joint damage, and kidney problems. Allopurinol is also used in adults and children with leukemia, lymphoma, and solid tumors who are getting cancer treatment. It helps manage high uric acid caused by the cancer treatment. It can also help adults who get calcium oxalate kidney stones often.

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
allopurinol

Allopurinol works by blocking an enzyme called xanthine oxidase. This enzyme helps your body make uric acid. By blocking it, allopurinol reduces the amount of uric acid in your blood and urine.

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
allopurinol
  • Diarrhea
  • Nausea
  • Increased liver enzyme levels
  • Gout attacks
  • Skin rash
theophylline
  • Nausea
  • Vomiting
  • Headache
  • Trouble sleeping (insomnia)
FAERS Reports
allopurinol
  • Diarrhea 8,423
  • Tiredness 7,965
  • Difficulty breathing 7,659
  • Feeling sick to your stomach 7,061
  • Death 6,664
theophylline
  • Difficulty breathing 2,273
  • Asthma 1,942
  • Pneumonia 1,317
  • Wheezing 1,306
  • Vomiting 1,101
Serious Warnings
allopurinol

Allopurinol can cause serious skin reactions that can be deadly. Stop taking this medicine and get medical help right away if you get a skin rash or any other signs of an allergic reaction.

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
allopurinol

Allopurinol may harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is not recommended to breastfeed while taking this medicine because it can pass into breast milk.

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

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How to Read This allopurinol vs theophylline Comparison

allopurinol is classified in the Xanthine Oxidase Inhibitor 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, allopurinol has 37,772 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 minor interaction flagged in FDA labeling, attributed to taking high doses of allopurinol can make it harder for the body to get rid of theophylline. this can lead to higher levels of theophylline in your system.. 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 allopurinol 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.