Enalapril and Allopurinol: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Allopurinol
Enalapril
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Hypersensitivity reactions (Stevens-Johnson syndrome, skin eruptions, anaphylactic coronary spasm)
Interaction Deep Dive
The coadministration of enalapril and allopurinol caused severe coronary vasospasm that culminated in acute myocardial infarction in a 50-year-old man1. Monitor carefully for hypersensitivity reactions when allopurinol and enalapril are used together.
Why it happens (mechanism)
Unknown
Literature reports
1 report — tap to read
a) A 50-year-old man with a history of hypertensive cardiovascular disease and gout was admitted to the hospital after allopurinol was added to his enalapril and furosemide regimen. Within 20 minutes of taking the first dose of allopurinol, the patient experienced generalized pruritus, urticaria, severe chest pain, nausea, peripheral cyanosis, hypotension, sinus tachycardia, and mild bronchospasm. Emergency measures were instituted to alleviate his anaphylaxis. Electrocardiograms and cardiac enzyme levels also indicated evidence of acute myocardial infarction. However, left and right coronary arteriograms were normal. The anaphylaxis and coronary spasm, culminating in myocardial infarction, were attributed to the coadministration of enalapril and allopurinol 1.
Common questions
Can I take Enalapril and Allopurinol together?
Hypersensitivity reactions (Stevens-Johnson syndrome, skin eruptions, anaphylactic coronary spasm) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Enalapril and Allopurinol interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Enalapril or Allopurinol need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Ahmad S: Allopurinol and enalapril. Drug induced anaphylactic coronary spasm and acute myocardial infarction (letter). Chest 1995; 108:586. DOI
Keep reading about Allopurinol
Keep reading about Enalapril
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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