Terazosin and Allopurinol Interaction
Drug interaction information between Terazosin and Allopurinol.
Terazosin and Allopurinol have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Terazosin and Allopurinol. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
These medications have been used together in clinical trials without any reported problems. There is no known negative interaction between them.
What To Do
You can continue taking both medications as prescribed. No special monitoring is usually necessary for this combination.
FDA Label Information
Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...
Terazosin Also Interacts With
- Hydrochlorothiazide minor
- Ibuprofen minor
- Aspirin minor
- Atenolol minor
- Acetaminophen minor
Allopurinol Also Interacts With
- Pegloticase major
- Cyclosporine moderate
- Amoxicillin moderate
- Amoxicillin/Clavulanate moderate
- Warfarin minor
Frequently Asked Questions
Can I take Terazosin and Allopurinol together?
This is a minor interaction. You can continue taking both medications as prescribed. No special monitoring is usually necessary for this combination.
How serious is the interaction between Terazosin and Allopurinol?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Terazosin and Allopurinol interact?
These medications have been used together in clinical trials without any reported problems. There is no known negative interaction between them.
Understanding the Terazosin and Allopurinol Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Terazosin belongs to the Alpha-1 Blocker class and Allopurinol belongs to the Xanthine Oxidase Inhibitor class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These medications have been used together in clinical trials without any reported problems. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Terazosin has 15 total documented interactions on file in this dataset, and Allopurinol has 10. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: You can continue taking both medications as prescribed. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Terazosin or Allopurinol based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.