What the FDA labels say about taking them together
Buspirone and ritonavir
Buspirone's FDA label of December 22, 2023 names ritonavir in its drug interactions section, and ritonavir's label names buspirone too. The ritonavir label: “A dose decrease may be needed for these drugs when co-administered with ritonavir.”
Check it at the source: the buspirone FDA label on DailyMed (effective December 22, 2023, Unichem Pharmaceuticals (USA), Inc.); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the buspirone label say about ritonavir?
Buspirone label, drug interactionsOther Inhibitors and Inducers of CYP3A4 Substances that inhibit CYP3A4, such as ketoconazole or ritonavir, may inhibit buspirone metabolism and increase plasma concentrations of buspirone while substances that induce CYP3A4, such as dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism.
Source: FDA drug label (Buspirone Hydrochloride), Unichem Pharmaceuticals (USA), Inc., effective December 22, 2023 (SPL set a6bdf140-075e-445e-a62d-633a4b97f3a8), via openFDA; the full label on DailyMed
What does the ritonavir label say about buspirone?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Sedative/hypnotics: buspirone, clorazepate, diazepam, estazolam, flurazepam, zolpidem; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ sedative/hypnotics; Clinical Comment: A dose decrease may be needed for these drugs when co-administered with ritonavir.
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
| Buspirone | Ritonavir | |
|---|---|---|
| Labeled for | Anxiety | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.043 per tablet 15 mg tablet | $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