What the FDA labels say about taking them together
Phenobarbital and stiripentol
Stiripentol's FDA label of April 27, 2026 names phenobarbital in its drug interactions section; the phenobarbital labels PlainMeds reads (2) do not name stiripentol. The stiripentol label: “… a potent CYP1A2, CYP3A4, or CYP2C19 inducer, such as rifampin, phenytoin, phenobarbital and carbamazepine, as these enzymes all metabolize stiripentol.”
Check it at the source: the phenobarbital FDA label on DailyMed (effective August 27, 2026); the stiripentol FDA label on DailyMed (effective April 27, 2026, BIOCODEX, INC.).
What does the phenobarbital label say about stiripentol?
Phenobarbital's label (effective August 27, 2026) and its 1 other brand-application label do not name stiripentol in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenobarbital), Chartwell RX, LLC, effective August 27, 2026 (SPL set 74428144-fb24-40a5-a670-3b876e2d116c), via openFDA; the full label on DailyMed
What does the stiripentol label say about phenobarbital?
Stiripentol label, drug interactionsDrugs on DIACOMIT Induction-based interactions leading to decreases in DIACOMIT concentrations are possible when co-administered with a potent CYP1A2, CYP3A4, or CYP2C19 inducer, such as rifampin, phenytoin, phenobarbital and carbamazepine, as these enzymes all metabolize stiripentol.
Source: FDA drug label (Diacomit), BIOCODEX, INC., effective April 27, 2026 (SPL set 58304ba8-9779-4658-811e-94ffe08c3f16), 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
| Phenobarbital | Stiripentol | |
|---|---|---|
| Labeled for | Seizures and epilepsy | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.213 per tablet 100 mg tablet | n/a |
| Shortage now | A presentation being discontinued | 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