What the FDA labels say about taking them together
Guanfacine and ketoconazole
Guanfacine's FDA label of June 23, 2025 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name guanfacine. The guanfacine label: “Consider dose reduction”
Check it at the source: the guanfacine FDA label on DailyMed (effective June 23, 2025, Takeda Pharmaceuticals America, Inc.); the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC).
What does the guanfacine label say about ketoconazole?
Guanfacine label, drug interactionsConcomitant Drug Name or Drug Class: Strong and moderate CYP3A4 inhibitors, e.g., ketoconazole, fluconazole; Clinical Rationale and Magnitude of Drug Interaction: Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in an increase in exposure; Clinical Recommendation: Consider dose reduction [see ]
Source: FDA drug label (Intuniv), Takeda Pharmaceuticals America, Inc., effective June 23, 2025 (SPL set b972af81-3a37-40be-9fe1-3ddf59852528), via openFDA; the full label on DailyMed
What does the ketoconazole label say about guanfacine?
Ketoconazole's label (effective January 28, 2026) does not name guanfacine 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
| Guanfacine | Ketoconazole | |
|---|---|---|
| Labeled for | ADHD, High blood pressure | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.147 per tablet 1 mg tablet | $0.249 per gram 2% cream |
| 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