Ritonavir and Telmisartan and amlodipine interaction
Ritonavir and Telmisartan and amlodipine: 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 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.
Calcium channel blockers: diltiazem, nifedipine, verapamil ↑ calcium channel blockers Caution is warranted and clinical monitoring of patients is recommended.
From the Telmisartan and amlodipine label · effective 2023-01-30
CYP3A4 Inhibitors Co-administration of a 180 mg daily dose of diltiazem with 5 mg amlodipine in elderly hypertensive patients resulted in a 60% increase in amlodipine systemic exposure.
However, strong inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, ritonavir) may increase the plasma concentrations of amlodipine to a greater extent.
Monitor for symptoms of hypotension and edema when amlodipine is co-administered with CYP3A4 inhibitors.
Patients should be monitored for adequate clinical effect when amlodipine is co-administered with CYP3A4 inducers.
CYP3A4 Inducers No information is available on the quantitative effects of CYP3A4 inducers ( e.g., carbamazepine, phenobarbital, phenytoin, fosphenytoin, primidone, rifampicin, St.
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.