Acetaminophen And Codeine and Triamterene: 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
Triamterene
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 a pain medicine that contains codeine along with acetaminophen, plus a water pill called triamterene. Codeine can cause your body to hold onto a little more water by nudging up a hormone that tells your kidneys to keep fluid. Because of that, your water pill may not work quite as well while you're using both.
In real life this might show up as making less urine than usual, or your blood pressure creeping up. The good news is this is easy for your care team to keep an eye on. Keep taking both medicines as prescribed, and let your pharmacist or doctor know if you notice swelling, less urination, or blood pressure changes. They can adjust things as needed.
Effect: Codeine may reduce triamterene's diuretic efficacy.
Mechanism: Opioid-mediated stimulation of antidiuretic hormone (ADH) release promotes water retention, opposing the diuretic's action. This is a PD (not PK) interaction. Codeine is a prodrug activated via CYP2D6, but that is not the driver here.
Evidence: Theoretical; onset unspecified; severity rated major.
- Monitor urine output, edema, weight, and blood pressure.
- Diuretic dose may be adjusted and individualized upward if diminished diuresis is observed.
- Reassess after opioid initiation or dose changes, and again if codeine is discontinued.
What happens
Reduced diuretic efficacy
Interaction Deep Dive
When codeine is taken alongside diuretics, the diuretic effect may be lessened because codeine can 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
This interaction is manageable with monitoring. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise.
What your care team may do:
- Watch how well your water pill is working (urine output, swelling, weight, blood pressure).
- Adjust and individualize your triamterene dose if needed to keep it effective.
- Recheck things when your codeine dose starts, changes, or stops.
What to raise with your pharmacist or prescriber:
- New or worse swelling in the legs, ankles, or hands.
- Noticeably less urination or higher blood pressure readings.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Triamterene together?
Codeine can slightly reduce how well triamterene removes fluid by raising an antidiuretic hormone, so watch for swelling, less urination, or higher blood pressure and let your care team adjust the water pill if needed. Keep taking both as prescribed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Triamterene 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 Triamterene interaction managed?
This interaction is manageable with monitoring. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. What your care team may do: Watch how well your water pill is working (urine output, swelling, weight, blood pressure). Adjust and individualize your triamterene dose if needed to keep it effective. Recheck things when your codeine dose starts, changes, or sto… 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.
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine or Triamterene 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 Triamterene
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist