Buprenorphine and Cyclopenthiazide: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Buprenorphine
Cyclopenthiazide
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.
Here's what's going on. Buprenorphine is an opioid pain medicine, and cyclopenthiazide is a water pill (diuretic) that helps your body get rid of extra fluid and can lower blood pressure. When these are taken together, the opioid may cause your body to hold onto more water, which can make the water pill work a little less well.
The good news is this is based mostly on theory, not strong real-world proof, so please don't worry. Don't stop or change either medicine on your own. Your care team can watch your blood pressure and how well the water pill is working, and adjust things if needed.
Effect: Opioids such as buprenorphine may reduce the efficacy of thiazide diuretics like cyclopenthiazide.
Mechanism: Opioid-induced release of antidiuretic hormone (ADH/vasopressin) promotes water retention, opposing the diuretic and antihypertensive PD effect. This is a pharmacodynamic interaction, not enzyme- or transporter-based; neither agent's metabolism is central here.
- Direction: reduced diuretic effect
- Onset: unspecified
- Evidence: theoretical
- Management: Monitor diuresis, fluid status, and blood pressure. The diuretic dose may need to be adjusted and individualized by the care team if diminished response is observed.
What happens
Reduced efficacy of diuretics
Interaction Deep Dive
When opioids such as buprenorphine are given together with diuretics, the diuretic's effectiveness may be lowered because the opioid triggers the release of antidiuretic hormone. Watch patients for indications of reduced diuresis and/or changes in blood pressure, and raise the diuretic dose when required1.
Why it happens (mechanism)
Induction of antidiuretic hormone release
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.
- Your team may monitor you more closely for how well the water pill is working, including your blood pressure and any swelling or fluid buildup.
- If the diuretic seems less effective, the dose may be adjusted and individualized by your care team.
- Tell your pharmacist or doctor if you notice swelling in your legs or ankles, sudden weight gain, less urination, or rising blood pressure.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Cyclopenthiazide together?
Buprenorphine may make your water pill (cyclopenthiazide) work a bit less well by causing fluid retention, but this is theoretical. Keep taking both as prescribed and let your care team monitor your blood pressure and fluid status. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Cyclopenthiazide 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 Buprenorphine and Cyclopenthiazide 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. Your team may monitor you more closely for how well the water pill is working, including your blood pressure and any swelling or fluid buildup. If the diuretic seems less effective, the dose may be adjusted and individualized by your care team. Tel… 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 Buprenorphine or Cyclopenthiazide 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: BRIXADI(TM) subcutaneous extended-release injection, buprenorphine subcutaneous extended-release injection. Braeburn Inc (per FDA), Plymouth Meeting, PA, 2023. DailyMed
Keep reading about Buprenorphine
Keep reading about Cyclopenthiazide
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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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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