What the FDA labels say about taking them together
Phenobarbital and rilpivirine
Rilpivirine's FDA label of August 28, 2025 names phenobarbital in its contraindications section; the phenobarbital labels PlainMeds reads (2) do not name rilpivirine. The rilpivirine label: “Coadministration is contraindicated with EDURANT or EDURANT PED.”
Check it at the source: the phenobarbital FDA label on DailyMed (effective August 27, 2026); the rilpivirine FDA label on DailyMed (effective August 28, 2025, Janssen Products, LP).
What does the phenobarbital label say about rilpivirine?
Phenobarbital's label (effective August 27, 2026) and its 1 other brand-application label do not name rilpivirine 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 rilpivirine label say about phenobarbital?
Rilpivirine label, contraindicationsDrug Class: Anticonvulsants; Contraindicated Drugs in Class: Carbamazepine Oxcarbazepine Phenobarbital Phenytoin; Clinical Comment: Potential for significant decreases in rilpivirine plasma concentrations due to CYP3A enzyme induction, which may result in loss of virologic response.
Rilpivirine label, drug interactionsConcomitant Drug Class/Drug Name: Anticonvulsants: carbamazepine oxcarbazepine phenobarbital phenytoin; Effect on Concentration of Rilpivirine or Concomitant Drug: ↓ rilpivirine; Clinical Comment: Coadministration is contraindicated with EDURANT or EDURANT PED [see ].
Source: FDA drug label (EDURANT), Janssen Products, LP, effective August 28, 2025 (SPL set 03880372-2c68-45c6-a53a-f420c49541d6), 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 | Rilpivirine | |
|---|---|---|
| Labeled for | Seizures and epilepsy | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.213 per tablet 100 mg tablet | $48.04 per tablet 25 mg tablet |
| 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