What the FDA labels say about taking them together
Buprenorphine and ritonavir
Buprenorphine's FDA label of June 5, 2026 names ritonavir in its drug interactions section; the ritonavir label PlainMeds reads does not name buprenorphine. The buprenorphine label: “The effects on buprenorphine exposure in patients treated with BRIXADI have not been studied, and the effects may be dependent on the route of administration. …”
Check it at the source: the buprenorphine FDA label on DailyMed (effective June 5, 2026); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the buprenorphine label say about ritonavir?
Buprenorphine label, drug interactionsInhibitors of CYP3A4 Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inhibitors can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when an inhibitor is added after a stable dose of buprenorphine sublingual tablets is achieved. … antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir)
Brixadi label (Braeburn Inc., December 31, 2025), drug interactionsInhibitors of CYP3A4 Clinical Impact: The effects on buprenorphine exposure in patients treated with BRIXADI have not been studied, and the effects may be dependent on the route of administration. Buprenorphine is metabolized to norbuprenorphine primarily by CYP3A4; … antifungals (e.g., ketoconazole), macrolide antibiotics (e.g., erythromycin), and protease inhibitors (e.g., ritonavir, indinavir, and saquinavir)
Sublocade label (Indivior Inc., July 27, 2026), drug interactionsInhibitors of CYP3A4 Clinical Impact: The effects of co-administered CYP3A4 inhibitors on buprenorphine exposure in subjects treated with SUBLOCADE have not been studied and the effects may be dependent on the route of administration; however, such interactions have been established in studies using transmucosal buprenorphine. … antifungals such as ketoconazole, macrolide antibiotics such as erythromycin, and HIV protease inhibitors (e.g., ritonavir, indinavir, and saquinavir)] should be monitored to ensure that the plasma buprenorphine level provided by SUBLOCADE is adequate. …
Source: FDA drug label (Brixadi, NDA210136), Braeburn Inc., effective December 31, 2025 (SPL set 5d8a8fd0-8619-422a-a664-d1d2e8970f48), via openFDA
Source: FDA drug label (Butrans, NDA021306), Knoa Pharma LLC, effective May 1, 2026 (SPL set 794aa355-66de-41b8-aedf-f2c40f6bc664), via openFDA
Source: FDA drug label (Sublocade, NDA209819), Indivior Inc., effective July 27, 2026 (SPL set 6189fb21-9432-45f8-8481-0bfaf3ccde95), via openFDA
Source: FDA drug label (Buprenorphine HCl), SpecGx LLC, effective June 5, 2026 (SPL set b60d514d-a88a-4fa2-a5b0-30ac29e04973), via openFDA; the full label on DailyMed
What does the ritonavir label say about buprenorphine?
Ritonavir's label (effective July 23, 2026) does not name buprenorphine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), 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
| Buprenorphine | Ritonavir | |
|---|---|---|
| Labeled for | Opioid use disorder, Pain | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.277 per tablet 2 mg tablet sl | $0.607 per tablet 100 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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