Acetaminophen And Codeine and Spironolactone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Spironolactone
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.
You're taking spironolactone (a water pill that helps your body get rid of extra fluid and control blood pressure) along with a codeine and acetaminophen pain medicine. The concern here is that codeine, an opioid, may nudge your body to hold onto more water by releasing a hormone that tells your kidneys to keep fluid. That could make your water pill work a little less well.
It's worth knowing this is a theoretical concern, meaning it's based on how the drugs work rather than strong real-world proof. Please don't change anything on your own. Your care team can easily keep an eye on your fluid levels and blood pressure and adjust your dose if needed.
Effect: Potential reduction in spironolactone diuretic efficacy.
Mechanism: Opioid (codeine) mediated release of antidiuretic hormone (ADH), promoting water retention and opposing the diuretic/antihypertensive effect. This is a pharmacodynamic interaction, not a metabolic one. Codeine is a prodrug activated via CYP2D6, but that pathway is not relevant here.
- Direction: reduced diuretic response.
- Onset: unspecified.
- Evidence: theoretical; severity rated major on file.
- Management: monitor diuresis, fluid status, edema, and blood pressure. Spironolactone dose may be individualized and titrated upward if diminished response is observed.
What happens
Reduced diuretic efficacy
Interaction Deep Dive
Taking codeine alongside diuretics can lessen how well the diuretics work, since codeine may trigger the release of anti-diuretic hormone. Watch patients for indications of reduced diuresis and/or changes in blood pressure, and raise the diuretic dose when necessary1.
Why it happens (mechanism)
Increased opioid-mediated release of antidiuretic hormone
How to manage this interaction
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This interaction is theoretical, and your care team can manage it well.
- Your team may monitor you more closely for signs the water pill is working less, such as more swelling, weight gain from fluid, or higher blood pressure.
- Your spironolactone dose may need to be adjusted and individualized if reduced effect is seen.
- Tell your pharmacist or doctor if you notice new swelling in your legs or feet, sudden weight gain, or blood pressure readings that run higher than usual.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Spironolactone together?
Codeine may slightly reduce how well your spironolactone works by causing fluid retention, but this is a theoretical concern your care team can manage with monitoring and dose adjustment if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Spironolactone interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Acetaminophen And Codeine and Spironolactone interaction managed?
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This interaction is theoretical, and your care team can manage it well. Your team may monitor you more closely for signs the water pill is working less, such as more swelling, weight gain from fluid, or higher blood pressure. Your spironolactone dose may need to be adjusted and individualized if reduced effect is… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine or Spironolactone 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)
- Product Information: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Spironolactone
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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