What the FDA labels say about taking them together
Oxcarbazepine and rifampin
Oxcarbazepine's FDA label of December 16, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name oxcarbazepine. The oxcarbazepine label: “Drugs on TRILEPTAL Strong inducers of cytochrome P450 enzymes and/or inducers of UGT have been shown to decrease the plasma/serum levels of MHD, the active metabolite of TRILEPTAL (25% to 49%).”
Check it at the source: the oxcarbazepine FDA label on DailyMed (effective December 16, 2025, Novartis Pharmaceuticals Corporation); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the oxcarbazepine label say about rifampin?
Oxcarbazepine label, drug interactionsDrugs on TRILEPTAL Strong inducers of cytochrome P450 enzymes and/or inducers of UGT (e.g., rifampin, carbamazepine, phenytoin and phenobarbital) have been shown to decrease the plasma/serum levels of MHD, the active metabolite of TRILEPTAL (25% to 49%) [see Clinical Pharmacology (12.3)].
Oxtellar Xr label (Supernus Pharmaceuticals, Inc., October 22, 2025), drug interactionsDrugs on Oxtellar XR If Oxtellar XR and strong CYP3A4 inducers or UGT inducers (e.g., rifampin, carbamazepine, phenytoin and phenobarbital) are administered concurrently, it is recommended that the plasma levels of MHD be monitored during the period of Oxtellar XR titration [see Clinical Pharmacology (12.3) ].
Source: FDA drug label (Oxtellar Xr, NDA202810), Supernus Pharmaceuticals, Inc., effective October 22, 2025 (SPL set aa610e56-1d1d-11e1-8bc2-0800200c9a66), via openFDA
Source: FDA drug label (Trileptal), Novartis Pharmaceuticals Corporation, effective December 16, 2025 (SPL set 4c5c86c8-ab7f-4fcf-bc1b-5a0b1fd0691b), via openFDA; the full label on DailyMed
What does the rifampin label say about oxcarbazepine?
Rifampin's label (effective February 11, 2026) does not name oxcarbazepine 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
| Oxcarbazepine | Rifampin | |
|---|---|---|
| Labeled for | Seizures and epilepsy | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.167 per tablet 300 mg tablet | $0.679 per capsule 300 mg capsule |
| Shortage now | No current entry | 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