What the FDA labels say about taking them together
Enzalutamide and rifabutin
Enzalutamide's FDA label (Xtandi) of May 25, 2021 names rifabutin in its drug interactions section; the rifabutin label PlainMeds reads does not name enzalutamide.
Check it at the source: the enzalutamide FDA label on DailyMed (effective July 28, 2026, Astellas Pharma US, Inc.); the rifabutin FDA label on DailyMed (effective September 1, 2026, REMEDYREPACK INC.).
What does the enzalutamide label say about rifabutin?
Xtandi label (Astellas Pharma US, Inc., May 25, 2021), drug interactionsCo-administration of strong CYP3A4 inducers (e.g., carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine) with XTANDI should be avoided if possible.
Source: FDA drug label (Xtandi, NDA213674), Astellas Pharma US, Inc., effective May 25, 2021 (SPL set 381cd215-78c9-4208-8595-7ae7a279b236), via openFDA
Source: FDA drug label (Xtandi), Astellas Pharma US, Inc., effective July 28, 2026 (SPL set b129fdc9-1d8e-425c-a5a9-8a2ed36dfbdf), via openFDA; the full label on DailyMed
What does the rifabutin label say about enzalutamide?
Rifabutin's label (effective September 1, 2026) does not name enzalutamide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Rifabutin), NDA050689 (Pfizer), as published by REMEDYREPACK INC., effective September 1, 2026 (SPL set 25a60937-cbbe-4a50-994f-2ce15203f589), 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
| Enzalutamide | Rifabutin | |
|---|---|---|
| Labeled for | Prostate cancer | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $8.14 per capsule 150 mg capsule |
| Shortage now | No current entry | No current entry |
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