Amiloride and Acetaminophen And Codeine: 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
Amiloride
No brand names on record
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've been prescribed a pain medicine that contains codeine (mixed with acetaminophen) along with amiloride, a water pill that helps your body get rid of extra fluid. Here's the concern: opioids like codeine can trigger your body to hold onto more water. In theory, that could make your water pill work a little less well, so you might notice less fluid coming off or small changes in your blood pressure.
This connection is theoretical, meaning it hasn't been strongly proven in people, so please don't worry. Keep taking both exactly as prescribed. Your care team can easily watch for this and adjust things if needed.
Effect: Potential reduction in amiloride's diuretic efficacy when combined with codeine (in the acetaminophen/codeine product).
Mechanism: Opioid-mediated increase in antidiuretic hormone (ADH) release promotes water retention, opposing the diuretic effect. This is a PD interaction; codeine is a CYP2D6 prodrug for its opioid activity, but that does not alter the direction here.
- Direction: Reduced diuretic response.
- Onset: Unspecified.
- Evidence: Theoretical; severity rated major on file.
- Management: Monitor diuresis, fluid status, and blood pressure. Diuretic dose may be adjusted and individualized as needed.
What happens
Reduced diuretic efficacy
Interaction Deep Dive
Concomitant use of codeine with diuretics may reduce the efficacy of diuretics by inducing the release of anti-diuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed1.
Why it happens (mechanism)
Increased opioid-mediated release of antidiuretic hormone
How to manage this interaction
Good news: this is a manageable situation, and codeine is often used only short-term for pain.
- Keep taking both exactly as prescribed unless your care team tells you otherwise.
- Your team may monitor you more closely for signs your water pill is working less well, such as swelling, weight gain, or changes in blood pressure.
- If needed, the amiloride dose may be adjusted and individualized by your care team.
- Tell your pharmacist or prescriber if you notice new swelling in your legs or feet, sudden weight gain, or feel your blood pressure medicine seems less effective.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amiloride and Acetaminophen And Codeine together?
Codeine may slightly weaken how well amiloride removes fluid, but this is only a theoretical concern. Keep taking both as prescribed and let your care team monitor your fluid status and blood pressure. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amiloride and Acetaminophen And Codeine 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 Amiloride and Acetaminophen And Codeine interaction managed?
Good news: this is a manageable situation, and codeine is often used only short-term for pain. Keep taking both exactly as prescribed unless your care team tells you otherwise. Your team may monitor you more closely for signs your water pill is working less well, such as swelling, weight gain, or changes in blood pressure. If needed, the amiloride dose may be adjusted and individualized by your ca… 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 Amiloride or Acetaminophen And Codeine 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 Amiloride
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major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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