What the FDA labels say about taking them together
Codeine and ketoconazole
Codeine's FDA label of December 22, 2025 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name codeine. The codeine label: “The concomitant use of Codeine Sulfate Tablets and CYP3A4 inducers can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels, resulting in decreased …”
Check it at the source: the codeine FDA label on DailyMed (effective December 22, 2025, Hikma Pharmaceuticals USA Inc.); the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC).
What does the codeine label say about ketoconazole?
Codeine label, drug interactionsClinical Impact: The concomitant use of Codeine Sulfate Tablets and CYP3A4 inducers can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels, resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. … Intervention: If concomitant use of a CYP3A4 inducer is necessary, evaluate patients at frequent intervals for reduced efficacy and signs of opioid withdrawal and consider increasing the Codeine Sulfate Tablets dosage as needed. …
Codeine label, warnings and precautionsCytochrome P450 3A4 Interaction: The concomitant use of Codeine Sulfate Tablets with all cytochrome P450 3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir) or discontinuation of a cytochrome P450 3A4 inducer such as rifampin, carbamazepine, and phenytoin, may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome P450 2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression.
Source: FDA drug label (Codeine sulfate), Hikma Pharmaceuticals USA Inc., effective December 22, 2025 (SPL set 010905f9-3bcb-4b50-9fe8-a3ad0010f14c), via openFDA; the full label on DailyMed
What does the ketoconazole label say about codeine?
Ketoconazole's label (effective January 28, 2026) does not name codeine 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
| Codeine | Ketoconazole | |
|---|---|---|
| Labeled for | Pain | Fungal infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.726 per tablet 30 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