What the FDA labels say about taking them together
Dexamethasone and rifampin
Dexamethasone's FDA label of June 6, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name dexamethasone. The dexamethasone label: “Drugs which induce cytochrome P450 3A4 (CYP 3A4) enzyme activity may enhance the metabolism of corticosteroids and require that the dosage of the corticosteroid be increased.”
Check it at the source: the dexamethasone FDA label on DailyMed (effective June 6, 2025, Hikma Pharmaceuticals USA, Inc.); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the dexamethasone label say about rifampin?
Dexamethasone label, drug interactionsDrugs which induce cytochrome P450 3A4 (CYP 3A4) enzyme activity (e.g., barbiturates, phenytoin, carbamazepine, rifampin) may enhance the metabolism of corticosteroids and require that the dosage of the corticosteroid be increased.
Source: FDA drug label (Dexamethasone Intensol), Hikma Pharmaceuticals USA, Inc., effective June 6, 2025 (SPL set b15200fb-1826-472b-a907-e677a272513b), via openFDA; the full label on DailyMed
What does the rifampin label say about dexamethasone?
Rifampin's label (effective February 11, 2026) does not name dexamethasone in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), 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
| Dexamethasone | Rifampin | |
|---|---|---|
| Labeled for | Asthma, Eczema (atopic dermatitis), Leukemia, lymphoma and myeloma, Herpes and shingles, Crohn's disease and ulcerative colitis, Multiple sclerosis, Osteoarthritis, Rheumatoid arthritis, Psoriasis, Allergies, Anemia, Pain | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.193 per tablet 4 mg tablet | $0.679 per capsule 300 mg capsule |
| Shortage now | In shortage | In shortage |
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