What the FDA labels say about taking them together
Estrogens conjugated and ketoconazole
Estrogens conjugated's FDA label of June 4, 2026 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name estrogens conjugated. The estrogens conjugated label: “Inhibitors of CYP3A4, such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice, may increase plasma concentrations of estrogens and may result in side effects.”
Check it at the source: the estrogens conjugated FDA label on DailyMed (effective June 4, 2026, Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.); the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC).
What does the estrogens conjugated label say about ketoconazole?
Estrogens conjugated label, drug interactionsInhibitors of CYP3A4, such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice, may increase plasma concentrations of estrogens and may result in side effects.
Source: FDA drug label (Premarin), Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., effective June 4, 2026 (SPL set 258e1602-a3cf-4ccc-ca80-73dbbfb812ff), via openFDA; the full label on DailyMed
What does the ketoconazole label say about estrogens conjugated?
Ketoconazole's label (effective January 28, 2026) does not name estrogens conjugated in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ketoconazole), E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC, effective January 28, 2026 (SPL set cad7c647-34a9-4e4e-83b3-8d78e58f588f), 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
| Estrogens conjugated | Ketoconazole | |
|---|---|---|
| Labeled for | Menopause symptoms, Breast cancer, Osteoporosis | Fungal infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $5.47 per tablet 0.625 mg tablet | $0.249 per gram 2% cream |
| 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