Colchicine and Paroxetine: 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
Paroxetine
Colchicine
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.
Let's talk about taking paroxetine (Paxil) together with colchicine. Colchicine is normally pushed out of your body by a kind of cellular pump. Paroxetine may slow that pump down, which can let colchicine build up to higher levels than intended. That matters because too much colchicine can cause serious problems like severe diarrhea, stomach pain, muscle weakness, and, in rare cases, life-threatening toxicity.
The good news is your care team can manage this. Please don't stop or change either medicine on your own. Instead, reach out to your pharmacist or doctor so they can review your kidney and liver health and decide the safest plan for you.
Effect: Increased colchicine exposure and risk of colchicine toxicity.
Mechanism: Colchicine is a P-gp (and CYP3A4) substrate. Paroxetine is proposed to inhibit P-gp-mediated colchicine efflux, reducing clearance and increasing systemic exposure. Neither agent is a prodrug; this raises the active colchicine level.
Evidence: Theoretical, extrapolated from documented toxicity with other P-gp/CYP3A4 inhibitors. Onset unspecified.
- Coadministration with a P-gp inhibitor is labeled contraindicated, and absolutely contraindicated in renal or hepatic impairment.
- If use is unavoidable in patients with normal renal/hepatic function, reduce colchicine daily dose or dosing frequency.
- Monitor closely for colchicine toxicity (GI symptoms, myopathy, cytopenias).
What happens
Increased colchicine exposure and an increased risk of colchicine toxicity
Interaction Deep Dive
As a substrate of both CYP3A4 and P-gp, colchicine has been linked to toxicities when given alongside clarithromycin, an agent that inhibits both CYP3A4 and P-gp. Such toxicities have likewise been seen when colchicine was combined with a CYP3A4 inhibitor and when it was combined with a P-gp inhibitor3. Because life-threatening and fatal colchicine toxicity has occurred in patients taking colchicine at therapeutic doses, the concurrent use of colchicine and P-gp inhibitors is contraindicated 1. This combination is likewise contraindicated in individuals with renal or hepatic impairment, since life-threatening and fatal drug interactions have been documented. When patients have normal renal and hepatic function 2 and coadministration of colchicine with a P-gp inhibitor cannot be avoided, the colchicine dose should be adjusted, either by lowering the daily dose or by decreasing how often it is given. Close monitoring for colchicine toxicity is warranted 3.
Why it happens (mechanism)
Inhibition of P-gp-mediated colchicine efflux transport
How to manage this interaction
Colchicine has a narrow safety margin, so higher levels can be dangerous. Here is how a care team typically handles this pairing:
- Do not stop or adjust either drug yourself. Keep taking both as prescribed until you speak with your prescriber or pharmacist.
- Your team will review your kidney and liver function, since combined use is not advised when these are impaired.
- If both drugs are still needed, the colchicine dose may be lowered or given less often, individualized by your care team.
- They may monitor you more closely for signs of colchicine toxicity such as diarrhea, vomiting, muscle pain or weakness.
Report these symptoms promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Colchicine and Paroxetine together?
Paroxetine can raise colchicine levels and the risk of serious toxicity, so combining them is generally contraindicated. Do not change either medicine on your own; contact your pharmacist or doctor to review the safest plan. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Paroxetine interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Colchicine and Paroxetine interaction managed?
Colchicine has a narrow safety margin, so higher levels can be dangerous. Here is how a care team typically handles this pairing: Do not stop or adjust either drug yourself. Keep taking both as prescribed until you speak with your prescriber or pharmacist. Your team will review your kidney and liver function, since combined use is not advised when these are impaired. If both drugs are still needed… 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 Colchicine or Paroxetine 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 (3)
- Product Information: LODOCO(R) oral tablets, colchicine oral tablets. AGEPHA Pharma USA, LLC (per FDA), Parsippany, NJ, 2023. DailyMed
- Product Information: COLCRYS oral tablets, colchicine oral tablets. Takeda Pharmaceuticals America Inc (per FDA), Deerfield, IL, 2020. DailyMed
- Product Information: GLOPERBA(R) oral solution, colchicine oral solution. Romeg Therapeutics LLC (per FDA), Woburn, MA, 2019. DailyMed
Keep reading about Paroxetine
Keep reading about Colchicine
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