What the FDA labels say about taking them together
Deflazacort and levothyroxine
Deflazacort's FDA label of November 13, 2025 names levothyroxine in its warnings and precautions section; levothyroxine's label does not name deflazacort itself but warns about its class (Corticosteroids). The deflazacort label: “When concomitant administration of corticosteroids and levothyroxine is required, administration of corticosteroid should precede the initiation of levothyroxine therapy to reduce the risk of adrenal crisis.”
Check it at the source: the deflazacort FDA label on DailyMed (effective November 13, 2025, PTC Therapeutics, Inc.); the levothyroxine FDA label on DailyMed (effective February 20, 2024, AbbVie Inc.).
What does the deflazacort label say about levothyroxine?
Deflazacort label, warnings and precautionsWhen concomitant administration of corticosteroids and levothyroxine is required, administration of corticosteroid should precede the initiation of levothyroxine therapy to reduce the risk of adrenal crisis.
Source: FDA drug label (EMFLAZA), PTC Therapeutics, Inc., effective November 13, 2025 (SPL set 31b347d2-f156-4055-9d8f-7cf0df420296), via openFDA; the full label on DailyMed
What does the levothyroxine label say about deflazacort?
Levothyroxine's label does not name deflazacort itself; it warns about its class (Corticosteroids):
Levothyroxine label, drug interactionsNephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration.
Source: FDA drug label (Synthroid), AbbVie Inc., effective February 20, 2024 (SPL set 1e11ad30-1041-4520-10b0-8f9d30d30fcc), 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
| Deflazacort | Levothyroxine | |
|---|---|---|
| Labeled for | n/a | Hypothyroidism |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $0.0588 per tablet 112 mcg 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