Cilostazol and Colchicine: 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
Cilostazol
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.
Here's what's going on. Cilostazol (Pletal) can slow down a liver enzyme called CYP3A4 that your body uses to break down colchicine. When that clean-up slows, colchicine can build up higher than intended. Too much colchicine can cause serious problems like bad diarrhea, stomach pain, muscle weakness, and effects on your blood counts.
This concern comes mostly from how the drugs work on paper rather than from lots of real-world cases, but because colchicine can be dangerous at high levels, it's worth taking seriously. Please don't stop or change either medicine on your own. Talk with your pharmacist or doctor. They can adjust your colchicine dose and keep an eye on you so you stay safe.
Mechanism: Cilostazol inhibits CYP3A4, reducing metabolic clearance of colchicine and increasing colchicine exposure (AUC/Cmax) and the risk of dose-related toxicity. Neither agent is a prodrug in a way that reverses this; colchicine accumulation is the concern.
- Direction: Increased colchicine effect/toxicity.
- Evidence: Theoretical; severity rated major given colchicine's narrow margin.
- Onset: Unspecified.
- Management: Avoid combination if possible. If necessary, reduce colchicine daily dose or dosing frequency and monitor for toxicity (GI symptoms, myopathy, neuropathy, myelosuppression). Greater caution with hepatic or renal impairment.
What happens
Increased colchicine exposure and an increased risk of colchicine-related toxicity
Interaction Deep Dive
Colchicine should not be taken together with CYP3A4 inhibitors because of the risk of severe, potentially fatal toxicity. When combined use of a CYP3A4 inhibitor and colchicine cannot be avoided, modify the colchicine dose by lowering either the amount given each day or how often it is administered, while closely watching the patient for signs of colchicine toxicity1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of colchicine
How to manage this interaction
How your care team can handle this:
- They may avoid using the two together when another option works.
- If you do need both, your colchicine dose may need to be adjusted and individualized, either a lower daily dose or less frequent dosing.
- Your team may monitor you more closely for signs of colchicine toxicity.
What you should do: Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Ask your pharmacist or doctor before starting this combination, and report any severe diarrhea, vomiting, muscle pain or weakness, numbness, or unusual tiredness right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Cilostazol and Colchicine together?
Cilostazol can raise colchicine levels and increase the risk of serious colchicine toxicity, so this combination is best avoided; if both are needed, your care team can lower the colchicine dose and monitor you closely. Never adjust either drug on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cilostazol and Colchicine 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 Cilostazol and Colchicine interaction managed?
How your care team can handle this: They may avoid using the two together when another option works. If you do need both, your colchicine dose may need to be adjusted and individualized, either a lower daily dose or less frequent dosing. Your team may monitor you more closely for signs of colchicine toxicity. What you should do: Keep taking both exactly as prescribed unless your prescriber tells y… 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 Cilostazol or Colchicine 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: MITIGARE(R) oral capsules, colchicine oral capsules. Hikma Specialty USA Inc (per FDA), Columbus, OH, 2024. DailyMed
Keep reading about Cilostazol
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