What the FDA labels say about taking them together
Rifampin and treprostinil
Treprostinil's FDA label of February 13, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name treprostinil. The treprostinil label: “Co-administration of the CYP2C8 enzyme inducer rifampin decreases exposure to treprostinil.”
Check it at the source: the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.); the treprostinil FDA label on DailyMed (effective February 13, 2025, Alembic Pharmaceuticals Inc.).
What does the rifampin label say about treprostinil?
Rifampin's label (effective February 11, 2026) does not name treprostinil 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
What does the treprostinil label say about rifampin?
Treprostinil label, drug interactionsCo-administration of the CYP2C8 enzyme inducer rifampin decreases exposure to treprostinil.
Source: FDA drug label (Tyvaso Dpi, NDA214324), United Therapeutics Corporation, effective November 20, 2025 (SPL set ddc3d400-bcb3-4b09-aae2-0768b10a5b0f), via openFDA
Source: FDA drug label (Treprostinil), Alembic Pharmaceuticals Inc., effective February 13, 2025 (SPL set 4a684b13-669d-4721-8ed4-30cc7762b0b8), 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
| Rifampin | Treprostinil | |
|---|---|---|
| Labeled for | n/a | Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.679 per capsule 300 mg capsule | n/a |
| Shortage now | In shortage | 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