What the FDA labels say about taking them together
Ketoconazole and sildenafil
Sildenafil's FDA label of November 17, 2023 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name sildenafil. The sildenafil label: “CYP3A4 inhibitors: Increase VIAGRA exposure ▪ Ritonavir:”
Check it at the source: the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC); the sildenafil FDA label on DailyMed (effective November 17, 2023, Viatris Specialty LLC).
What does the ketoconazole label say about sildenafil?
Ketoconazole's label (effective January 28, 2026) does not name sildenafil 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
What does the sildenafil label say about ketoconazole?
Sildenafil label, drug interactionsCYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin): Increase VIAGRA exposure ( 2.4 , 7.4 , 12.3 ) ▪ Ritonavir:
Vybrique label (IBSA Pharma Inc., July 8, 2026), drug interactionsDRUG INTERACTIONS VYBRIQUE can potentiate the hypotensive effects of nitrates, alpha blockers, and antihypertensives. ( 4.1 , 5.5 , 7.1 , 7.2 , 7.3 , 12.2 ) With concomitant use of alpha blockers, initiate VYBRIQUE at 25 mg dose. ( 2.2 ) CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin) increase VYBRIQUE exposure.
Source: FDA drug label (Vybrique, NDA210858), IBSA Pharma Inc., effective July 8, 2026 (SPL set 9213fec1-e0c0-4ef7-9718-d97922a3f4d8), via openFDA
Source: FDA drug label (Viagra), Viatris Specialty LLC, effective November 17, 2023 (SPL set d905dc8d-917f-4ea3-a4ee-a1ecf6967d4e), 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
| Ketoconazole | Sildenafil | |
|---|---|---|
| Labeled for | Fungal infections | Erectile dysfunction, Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.249 per gram 2% cream | $0.132 per tablet 100 mg tablet |
| 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