What the FDA labels say about taking them together
Irinotecan and rifapentine
Irinotecan's FDA label (Onivyde) of March 3, 2025 names rifapentine in its drug interactions section; the rifapentine label PlainMeds reads does not name irinotecan. The irinotecan label: “Avoid the use of strong CYP3A4 inducers if possible.”
Check it at the source: the irinotecan FDA label on DailyMed (effective May 12, 2026, Pharmacia & Upjohn Company LLC); the rifapentine FDA label on DailyMed (effective February 6, 2026, sanofi-aventis U.S. LLC).
What does the irinotecan label say about rifapentine?
Onivyde label (Ipsen Biopharmaceuticals, Inc., March 3, 2025), drug interactionsAvoid the use of strong CYP3A4 inducers (e.g., rifampin, phenytoin, carbamazepine, rifabutin, rifapentine, phenobarbital, St. John's wort) if possible.
Source: FDA drug label (Onivyde, NDA207793), Ipsen Biopharmaceuticals, Inc., effective March 3, 2025 (SPL set c8b58efa-1820-48a4-b70d-62918fc4abfc), via openFDA
Source: FDA drug label (Camptosar), NDA020571 (Pfizer Inc), as published by Pharmacia & Upjohn Company LLC, effective May 12, 2026 (SPL set e518dfc6-7e93-4fee-a66c-51e1ab71c056), via openFDA; the full label on DailyMed
What does the rifapentine label say about irinotecan?
Rifapentine's label (effective February 6, 2026) does not name irinotecan in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Priftin), sanofi-aventis U.S. LLC, effective February 6, 2026 (SPL set 3a64fb70-b85e-43d9-8bcd-7e893f568ae1), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Irinotecan | Rifapentine | |
|---|---|---|
| Labeled for | Colorectal cancer | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $4.83 per tablet 150 mg tablet |
| Shortage now | A presentation being discontinued | Resolved |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once