What the FDA labels say about taking them together
Gemfibrozil and treprostinil
Treprostinil's FDA label of February 13, 2025 names gemfibrozil in its drug interactions section; the gemfibrozil labels PlainMeds reads (2) do not name treprostinil. The treprostinil label: “… that co-administration of the cytochrome P450 (CYP) 2C8 enzyme inhibitor gemfibrozil increases exposure (both C max and AUC) to treprostinil.”
Check it at the source: the gemfibrozil FDA label on DailyMed (effective April 10, 2026, Northstar RxLLC); the treprostinil FDA label on DailyMed (effective February 13, 2025, Alembic Pharmaceuticals Inc.).
What does the gemfibrozil label say about treprostinil?
Gemfibrozil's label (effective April 10, 2026) and its 1 other brand-application label do 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 (Gemfibrozil), Northstar RxLLC, effective April 10, 2026 (SPL set 75cac02c-56e3-4dfe-b1e2-4ce166b28833), via openFDA; the full label on DailyMed
What does the treprostinil label say about gemfibrozil?
Treprostinil label, drug interactionsHuman pharmacokinetic studies with an oral formulation of treprostinil (treprostinil diolamine) indicated that co-administration of the cytochrome P450 (CYP) 2C8 enzyme inhibitor gemfibrozil increases exposure (both C max and AUC) to treprostinil.
Tyvaso Dpi label (United Therapeutics Corporation, November 20, 2025), warnings and precautionsDrugs on Treprostinil Co-administration of a cytochrome P450 (CYP) 2C8 enzyme inhibitor (e.g., gemfibrozil) may increase exposure (both C max and AUC) 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
| Gemfibrozil | Treprostinil | |
|---|---|---|
| Labeled for | High cholesterol, Heart attack and coronary artery disease | Pulmonary arterial hypertension |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.104 per tablet 600 mg tablet | n/a |
| Shortage now | A presentation being discontinued | 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