Prazosin and Allopurinol Interaction
Drug interaction information between Prazosin and Allopurinol.
Prazosin and Allopurinol have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Prazosin and Allopurinol. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
There is no evidence that these two medications cause problems when taken together.
FDA Label Information
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin,...
Prazosin Also Interacts With
- Aspirin minor
- Diazepam minor
- Digoxin minor
- Indomethacin minor
- Colchicine minor
Allopurinol Also Interacts With
- Pegloticase major
- Cyclosporine moderate
- Amoxicillin moderate
- Amoxicillin/Clavulanate moderate
- Warfarin minor
Frequently Asked Questions
What SPL severity band is on file for Prazosin + Allopurinol?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Prazosin has 11 labeled pairs on file vs Allopurinol's 10. In the minor band specifically: Prazosin has 11 (also Aspirin, Diazepam, Digoxin, Indomethacin); Allopurinol has 6 (also Warfarin, Theophylline, Ampicillin/Sulbactam, Famciclovir).
What mechanism field is on file for Prazosin and Allopurinol?
There is no evidence that these two medications cause problems when taken together.
Allopurinol carries more major-labeled pairs than Prazosin
SPL source-record counts only. This page's band is minor · classes on file: Prazosin (Alpha-1 Blocker); Allopurinol (Xanthine Oxidase Inhibitor).
Allopurinol has 1 major-labeled pair vs Prazosin's 0. This page itself is in the minor band, not the major band.
0 major · 0 moderate · 11 minor · 11 total
- Other minor peers for Prazosin
- Aspirin
- Diazepam
- Digoxin
- Indomethacin
1 major · 3 moderate · 6 minor · 10 total
- Other minor peers for Allopurinol
- Warfarin
- Theophylline
- Ampicillin/Sulbactam
- Famciclovir
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.