What the FDA labels say about taking them together
Estradiol and pentobarbital
Pentobarbital's FDA label of March 8, 2024 names estradiol in its drug interactions section; the estradiol labels PlainMeds reads (4) do not name pentobarbital. The pentobarbital label: “Estradiol, estrone, progesterone and other steroidal hormones: Pretreatment with or concurrent administration of phenobarbital may decrease the effect of estradiol by increasing its metabolism.”
Check it at the source: the estradiol FDA label on DailyMed (effective April 3, 2024, Amneal Pharmaceuticals LLC); the pentobarbital FDA label on DailyMed (effective March 8, 2024, Hikma Pharmaceuticals USA Inc.).
What does the estradiol label say about pentobarbital?
Estradiol's label (effective April 3, 2024) and its 3 other brand-application labels do not name pentobarbital in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (YUVAFEM), Amneal Pharmaceuticals LLC, effective April 3, 2024 (SPL set 30c7f6ba-7a9e-4853-b3e4-e00a46560224), via openFDA; the full label on DailyMed
What does the pentobarbital label say about estradiol?
Pentobarbital label, drug interactionsEstradiol, estrone, progesterone and other steroidal hormones: Pretreatment with or concurrent administration of phenobarbital may decrease the effect of estradiol by increasing its metabolism.
Source: FDA drug label (Pentobarbital Sodium), Hikma Pharmaceuticals USA Inc., effective March 8, 2024 (SPL set d375b92a-baa1-4d63-9ad1-1467dcfde7d5), 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
| Estradiol | Pentobarbital | |
|---|---|---|
| Labeled for | Menopause symptoms, Breast cancer, Osteoporosis | Insomnia |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0635 per tablet 1 mg tablet | n/a |
| 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