What the FDA labels say about taking them together
Propafenone and ritonavir
Propafenone's FDA label of September 1, 2025 names ritonavir in its drug interactions section, and ritonavir's label names propafenone too. The ritonavir label: “Contraindicated due to potential for cardiac arrhythmias.”
Check it at the source: the propafenone FDA label on DailyMed (effective September 1, 2025, Strides Pharma Science Limited); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the propafenone label say about ritonavir?
Propafenone label, drug interactionsDrugs that inhibit CYP2D6 (such as desipramine, paroxetine, ritonavir, or sertraline) and CYP3A4 (such as ketoconazole, ritonavir, saquinavir, erythromycin, grapefruit juice) can be expected to cause increased plasma levels of propafenone.
Propafenone label, warnings and precautionsDrugs that inhibit these CYP pathways (such as desipramine, paroxetine, ritonavir, sertraline for CYP2D6; ketoconazole, erythromycin, saquinavir, and grapefruit juice for CYP3A4; and amiodarone and tobacco smoke for CYP1A2) can be expected to cause increased plasma levels of propafenone.
Source: FDA drug label (PROPAFENONE HYDROCHLORIDE), Strides Pharma Science Limited, effective September 1, 2025 (SPL set c65253ab-937f-4982-b841-69c2b9f9ccdb), via openFDA; the full label on DailyMed
What does the ritonavir label say about propafenone?
Ritonavir label, contraindicationsNORVIR is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening reactions [see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )]. ○ Alpha 1- Adrenoreceptor Antagonist: alfuzosin ○ Antianginal: ranolazine ○ Antiarrhythmics: amiodarone, dronedarone, flecainide, propafenone, quinidine ○ Antifungal: voriconazole ○ Anti-gout: colchicine ○ Antipsychotics: lurasidone, pimozide ○ Ergot Derivatives: dihydroergotamine, ergotamine, methylergonovine ○ GI Motility Agent: cisapride ○ HMG-CoA Reductase Inhibitors: lovastatin, simvastatin ○ Microsomal triglyceride transfer …
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Antiarrhythmics: amiodarone, dronedarone, flecainide, propafenone, quinidine; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ antiarrhythmics; Clinical Comment: Contraindicated due to potential for cardiac arrhythmias [see Contraindications () ].
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
| Propafenone | Ritonavir | |
|---|---|---|
| Labeled for | Atrial fibrillation | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.115 per tablet 150 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