What the FDA labels say about taking them together
Lidocaine and ritonavir
Ritonavir's FDA label of July 23, 2026 names lidocaine in its drug interactions section; the lidocaine labels PlainMeds reads (4) do not name ritonavir. The ritonavir label: “Caution is warranted and therapeutic concentration monitoring is recommended for antiarrhythmics when co-administered with ritonavir, if available.”
Check it at the source: the lidocaine FDA label on DailyMed (effective May 13, 2024, Fresenius Kabi USA, LLC); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the lidocaine label say about ritonavir?
Lidocaine's label (effective May 13, 2024) and its 3 other brand-application labels do not name ritonavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Xylocaine MPF), Fresenius Kabi USA, LLC, effective May 13, 2024 (SPL set d5e0d06f-ba1e-44d4-aa89-39d6c146dc23), via openFDA; the full label on DailyMed
What does the ritonavir label say about lidocaine?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Antiarrhythmics: disopyramide, lidocaine, mexiletine; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ antiarrhythmics; Clinical Comment: Caution is warranted and therapeutic concentration monitoring is recommended for antiarrhythmics when co-administered with ritonavir, if available.
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
| Lidocaine | Ritonavir | |
|---|---|---|
| Labeled for | Pain | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.154 per gram 5% ointment | $0.607 per tablet 100 mg tablet |
| Shortage now | In shortage | 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