What the FDA labels say about taking them together
Ketoconazole and tinidazole
Tinidazole's FDA label of December 27, 2021 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name tinidazole. The tinidazole label: “Simultaneous administration of drugs that inhibit the activity of liver microsomal enzymes, i.e., CYP3A4 inhibitors such as cimetidine and ketoconazole, may prolong the half-life and decrease the plasma clearance of …”
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 tinidazole FDA label on DailyMed (effective December 27, 2021, Mission Pharmacal Company).
What does the ketoconazole label say about tinidazole?
Ketoconazole's label (effective January 28, 2026) does not name tinidazole 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 tinidazole label say about ketoconazole?
Tinidazole label, drug interactionsSimultaneous administration of drugs that inhibit the activity of liver microsomal enzymes, i.e., CYP3A4 inhibitors such as cimetidine and ketoconazole, may prolong the half-life and decrease the plasma clearance of tinidazole, increasing the plasma concentrations of tinidazole.
Source: FDA drug label (Tindamax), Mission Pharmacal Company, effective December 27, 2021 (SPL set a0d01539-8413-4703-94cc-d221918630a1), 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 | Tinidazole | |
|---|---|---|
| Labeled for | Fungal infections | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.249 per gram 2% cream | $2.35 per tablet 500 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