What the FDA labels say about taking them together
Gemfibrozil and montelukast
Gemfibrozil's FDA label of April 10, 2026 names montelukast in its drug interactions section, and montelukast's label names gemfibrozil too. The gemfibrozil label: “(C) CYP2C8 Substrates: Gemfibrozil is a strong inhibitor of CYP2C8 and may increase exposure of drugs mainly metabolized by CYP2C8.”
Check it at the source: the gemfibrozil FDA label on DailyMed (effective April 10, 2026, Northstar RxLLC); the montelukast FDA label on DailyMed (effective April 30, 2025, Organon LLC).
What does the gemfibrozil label say about montelukast?
Gemfibrozil label, drug interactions(C) CYP2C8 Substrates: Gemfibrozil is a strong inhibitor of CYP2C8 and may increase exposure of drugs mainly metabolized by CYP2C8 (e.g., dabrafenib, enzalutamide, loperamide, montelukast, paclitaxel, pioglitazone, rosiglitazone).
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 montelukast label say about gemfibrozil?
Montelukast label, drug interactionsDRUG INTERACTIONS No dose adjustment is needed when SINGULAIR is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, fexofenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3) ].
Source: FDA drug label (SINGULAIR), Organon LLC, effective April 30, 2025 (SPL set 482dcc92-b47f-4ea6-854a-f5ac2aea7842), 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 | Montelukast | |
|---|---|---|
| Labeled for | High cholesterol, Heart attack and coronary artery disease | Asthma, Allergies |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.104 per tablet 600 mg tablet | $0.0419 per tablet 10 mg tablet |
| Shortage now | A presentation being discontinued | A presentation being discontinued |
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