Amlodipine Interactions

Amlodipine is a CYP3A4 substrate, but unlike other dihydropyridines (felodipine, nisoldipine), its high oral bioavailability and slow elimination mean grapefruit juice does not meaningfully alter its pharmacokinetics in controlled trials. Some product labels and consumer references still list a theoretical interaction.

Theoretically, high doses of supplemental calcium could blunt the vasodilatory effect of calcium channel blockers such as amlodipine, but controlled human data are limited. Drugs.com flags this as a minor monitor-only interaction with weak clinical evidence.