Propranolol and Ritonavir interaction
Propranolol and Ritonavir: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Propranolol (InnoPran XL) label · effective 2026-08-27
Impact of Other Drugs on Propranolol CYP2D6, CYP1A2 and CYP2C19 Inhibitors: CYP2D6 inhibitors (e.g. bupropion, fluoxetine, paroxetine, quinidine), CYP1A2 inhibitors (e.g., ciprofloxacin, enoxamine, fluvoxamine) and CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) increase exposure to propranolol when co-administered with INNOPRAN XL.
CYP1A2 and CYP2C19 Inducers: CYP1A2 inducers (e.g., phenytoin, montelukast, smoking) and CYP2C19 inducers (e.g. rifampin) decrease the plasma levels of propranolol resulting in a loss of efficacy [see Clinical Pharmacology ( 12.7 )] .
From the Ritonavir (Norvir) label · effective 2026-07-23
The impact on the PR interval of co-administration of ritonavir with other drugs that prolong the PR interval (including calcium channel blockers, beta-adrenergic blockers, digoxin and atazanavir) has not been evaluated.
Initiation of quetiapine in patients taking NORVIR: Refer to the quetiapine prescribing information for initial dosing and titration of quetiapine. β-Blockers: metoprolol, timolol ↑ beta-blockers Caution is warranted and clinical monitoring of patients is recommended.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.