Amlodipine and Efavirenz, lamivudine, and tenofovir interaction
Amlodipine and Efavirenz, lamivudine, and tenofovir: 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 Amlodipine (NORLIQVA) label · effective 2026-02-16
Impact of Other Drugs on Amlodipine CYP3A Inhibitors Co-administration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction.
Monitor for symptoms of hypotension and edema when amlodipine is co-administered with CYP3A inhibitors to determine the need for dose adjustment [see Clinical Pharmacology (12.3) ] .
Blood pressure should be closely monitored when amlodipine is co-administered with CYP3A inducers.
CYP3A Inducers No information is available on the quantitative effects of CYP3A inducers on amlodipine.
From the Efavirenz, lamivudine, and tenofovir (SYMFI) label · effective 2019-10-15
Calcium channel blockers: Diltiazem ↓ diltiazem ↓ desacetyl diltiazem ↓ N-monodesmethyldiltiazem Diltiazem dose adjustments should be guided by clinical response (refer to the full prescribing information for diltiazem).
Others (e.g., felodipine, nicardipine, nifedipine, verapamil) ↓ calcium channel blocker When coadministered with EFV, dosage adjustment of calcium channel blocker may be needed and should be guided by clinical response (refer to the full prescribing information for the calcium channel blocker).
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.