What the FDA labels say about taking them together
Etrasimod arginine and rifampin
Etrasimod arginine's FDA label of August 18, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name etrasimod arginine. The etrasimod arginine label: “Clinical Impact; Concomitant use with a drug that is a combined CYP3A4 (strong), CYP2C8 (moderate) and CYP2C9 (moderate) inducer (i.e., rifampin) decreases exposure to etrasimod.”
Check it at the source: the etrasimod arginine FDA label on DailyMed (effective August 18, 2025, Pfizer Laboratories Div Pfizer Inc); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the etrasimod arginine label say about rifampin?
Etrasimod arginine label, drug interactionsClinical Impact; Concomitant use with a drug that is a combined CYP3A4 (strong), CYP2C8 (moderate) and CYP2C9 (moderate) inducer (i.e., rifampin) decreases exposure to etrasimod [see ].
Source: FDA drug label (Velsipity), Pfizer Laboratories Div Pfizer Inc, effective August 18, 2025 (SPL set 65171e4a-d136-4abc-b08c-c40c1b486ff6), via openFDA; the full label on DailyMed
What does the rifampin label say about etrasimod arginine?
Rifampin's label (effective February 11, 2026) does not name etrasimod arginine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), 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
| Etrasimod arginine | Rifampin | |
|---|---|---|
| Labeled for | Crohn's disease and ulcerative colitis | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.679 per capsule 300 mg capsule |
| Shortage now | No current entry | In shortage |
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