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What the FDA labels say about taking them together

Carbamazepine and sofosbuvir

Sofosbuvir's FDA label of December 26, 2024 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do not name sofosbuvir. The sofosbuvir label: “Coadministration of SOVALDI with carbamazepine, phenytoin, phenobarbital or oxcarbazepine is expected to decrease the concentration of sofosbuvir, leading to reduced therapeutic effect of SOVALDI. …”

Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the sofosbuvir FDA label on DailyMed (effective December 26, 2024, Gilead Sciences, Inc.).

What does the carbamazepine label say about sofosbuvir?

Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do not name sofosbuvir in these sections. A label lists what its studies and reports found; it is not a complete list.

Source: FDA drug label (Tegretol), Novartis Pharmaceuticals Corporation, effective August 20, 2026 (SPL set 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053), via openFDA; the full label on DailyMed

What does the sofosbuvir label say about carbamazepine?

Sofosbuvir label, drug interactions

Concomitant Drug Class/Drug Name: Anticonvulsants: Carbamazepine phenytoin phenobarbital oxcarbazepine; Effect on Concentration ↓ = decrease.: ↓ sofosbuvir ↓ GS-331007; Clinical Comment: Coadministration of SOVALDI with carbamazepine, phenytoin, phenobarbital or oxcarbazepine is expected to decrease the concentration of sofosbuvir, leading to reduced therapeutic effect of SOVALDI. Coadministration is not recommended.

Source: FDA drug label (Sovaldi), Gilead Sciences, Inc., effective December 26, 2024 (SPL set 80beab2c-396e-4a37-a4dc-40fdb62859cf), 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

42Carbamazepine generic labelers
0Sofosbuvir generic labelers
CarbamazepineSofosbuvir
Labeled forBipolar disorder, Seizures and epilepsyHepatitis C
Boxed warningYesYes
Pharmacy cost (NADAC)$0.119 per tablet 200 mg tabletn/a
Shortage nowA presentation being discontinuedNo 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?