Colchicine and Cobicistat: 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
Cobicistat
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.
Cobicistat (Tybost) can cause colchicine to build up in your body to dangerous levels. Your body normally breaks down and removes colchicine using an enzyme (CYP3A4) and a transporter (P-gp). Cobicistat blocks both of these, so colchicine can climb much higher than intended. That matters because too much colchicine can cause serious, even life-threatening problems, and there have been reports of fatal reactions.
The good news is this is very manageable. Do not stop either medicine on your own. Talk with your pharmacist or doctor. In some people this combination is avoided entirely, and in others the colchicine dose is lowered and you are watched closely.
Direction: Cobicistat, a dual strong CYP3A4 and P-gp inhibitor, reduces colchicine (a CYP3A4 and P-gp substrate) clearance, increasing colchicine exposure and risk of toxicity.
- Severity: Contraindicated, especially with renal or hepatic impairment. Fatal toxicity reported at therapeutic colchicine doses.
- Evidence: Theoretical/mechanistic, supported by case reports.
- Management: Avoid in renal/hepatic impairment. If co-administration is required with normal organ function, reduce colchicine dose or frequency and monitor for toxicity. Gout flare: 0.6 mg once, then 0.3 mg 1 hour later, no repeat sooner than 3 days. Prophylaxis: reduce to 0.3 mg daily or 0.3 mg every other day. FMF: max 0.6 mg/day.
What happens
Increased colchicine exposure and an increased risk of colchicine toxicity
Interaction Deep Dive
Both CYP3A4 and P-gp metabolize colchicine, which acts as a substrate for each. Because therapeutic doses of colchicine have produced life-threatening and fatal toxicity in patients receiving strong dual inhibitors of CYP3A4 and P-glycoprotein (P-gp), coadministering colchicine with such agents is contraindicated1. Likewise, in individuals with impaired renal or hepatic function, colchicine must not be combined with a dual CYP3A4 and P-gp inhibitor such as cobicistat. When such combined therapy is necessary in patients whose hepatic and renal function is normal, the colchicine dose must be modified, either by lowering the total daily amount or by decreasing how often it is given, while the patient is closely watched for signs of colchicine toxicity3. For patients free of renal or hepatic impairment who are being treated for a gout flare, reduce colchicine to a single 0.6 mg tablet followed one hour later by 0.3 mg (half a tablet), and do not repeat this course sooner than 3 days. For gout flare prophylaxis, cut the colchicine dose from an initial 0.6 mg twice daily to 0.3 mg once daily, or from an initial 0.6 mg once daily to 0.3 mg once every other day. When treating familial Mediterranean fever, keep the maximum daily colchicine dose at no greater than 0.6 mg (which may be administered as 0.3 mg twice daily)42.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of colchicine; inhibition of P-gp-mediated efflux transport of colchicine
How to manage this interaction
Keep taking both medicines exactly as prescribed until you speak with your care team. This combination is often avoided, and it should not be used at all if you have kidney or liver problems.
- Your team may decide to reduce your colchicine dose or how often you take it and watch you more closely for signs of toxicity.
- Watch for warning signs like severe diarrhea, vomiting, muscle weakness or pain, numbness, or unusual bruising, and report them promptly.
- Ask your pharmacist or prescriber whether this combination is right for you and whether an alternative is available.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) In a pharmacokinetic investigation, giving a single 0.6 mg dose of colchicine together with ketoconazole 200 mg twice daily over 5 days (a potent CYP3A4 inhibitor) raised the colchicine Cmax by 101.7% and the AUC by 212.2% relative to baseline values (N=24) 2.
b) When a 0.6 mg dose of colchicine was administered along with clarithromycin 250 mg twice daily for 7 days, the colchicine Cmax and AUC rose by 227.2% and 281.5%, respectively, from baseline in a study involving 23 patients 2.
Common questions
Can I take Colchicine and Cobicistat together?
Cobicistat can push colchicine to toxic, potentially fatal levels, so this combination is contraindicated (especially with kidney or liver problems). Do not change anything yourself; talk with your pharmacist or doctor about dose reduction, close monitoring, or an alternative. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colchicine and Cobicistat 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 Cobicistat interaction managed?
Keep taking both medicines exactly as prescribed until you speak with your care team. This combination is often avoided, and it should not be used at all if you have kidney or liver problems. Your team may decide to reduce your colchicine dose or how often you take it and watch you more closely for signs of toxicity. Watch for warning signs like severe diarrhea, vomiting, muscle weakness or pain,… 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 Colchicine or Cobicistat 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 (4)
- 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
- Product Information: SYMTUZA(R) oral tablets, darunavir, cobicistat, emtricitabine, tenofovir alafenamide oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
Keep reading about Cobicistat
Keep reading about Colchicine
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