What the FDA labels say about taking them together
Quinine and ritonavir
Quinine's FDA label of November 9, 2023 names ritonavir in its drug interactions (prescription label) section, and ritonavir's label names quinine too. The ritonavir label: “A dose decrease of quinine may be needed when co-administered with ritonavir.”
Check it at the source: the quinine FDA label on DailyMed (effective November 9, 2023); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the quinine label say about ritonavir?
Quinine label, drug interactions (prescription label)Ritonavir In healthy subjects who received a single oral 600 mg dose of quinine sulfate with the 15 th dose of ritonavir (200 mg every 12 hours for 9 days), there were 4-fold increases in the mean quinine AUC and C max, and an increase in the mean elimination half-life (13.4 hours versus 11.2 hours), compared to when quinine was given alone.
Source: FDA drug label (Chininum sulphuricum), Boiron, effective November 9, 2023 (SPL set 33885950-2a55-11e7-8288-424c58303031), via openFDA; the full label on DailyMed
What does the ritonavir label say about quinine?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Antiparasitic: quinine; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ quinine; Clinical Comment: A dose decrease of quinine may be needed 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
| Quinine | Ritonavir | |
|---|---|---|
| Labeled for | n/a | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.698 per capsule 324 mg capsule | $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