Grapefruit Juice Does Not Affect Norvasc (Amlodipine)
Grapefruit juice has no clinically significant effect on amlodipine (Norvasc) pharmacokinetics or pharmacodynamics, and patients can safely consume grapefruit products while taking this medication. 1, 2
Evidence from FDA Drug Label
The FDA-approved prescribing information for amlodipine explicitly states that "co-administered grapefruit juice has no impact on the exposure to amlodipine." 1 This is the highest quality evidence available and should guide clinical practice.
Why Amlodipine is Different from Other Calcium Channel Blockers
While grapefruit juice significantly increases blood levels of other dihydropyridine calcium channel blockers (felodipine, nifedipine, nisoldipine, nitrendipine) by 70% or more through CYP3A4 inhibition 3, 4, amlodipine behaves differently:
Amlodipine has exceptionally high baseline bioavailability (81-88%), meaning there is minimal first-pass metabolism to be affected by grapefruit juice 2
Clinical pharmacokinetic studies demonstrate no change in AUC, Cmax, clearance, or volume of distribution when amlodipine is co-administered with grapefruit juice 2
Blood pressure effects remain unchanged with grapefruit juice co-administration 2
Clinical Implications
Patients taking amlodipine do not need to avoid grapefruit juice or grapefruit products 1, 2
This distinguishes amlodipine from other calcium channel blockers like felodipine, nifedipine, and verapamil, where grapefruit avoidance is mandatory due to risk of excessive vasodilation and hypotension 5, 4
Amlodipine can be used as an alternative calcium channel blocker for patients who wish to continue consuming grapefruit products 4
Common Pitfalls to Avoid
Do not extrapolate grapefruit interactions from other dihydropyridines to amlodipine—the pharmacokinetic profile is fundamentally different 2
While one case report suggested rapid blood pressure decrease with nifedipine and grapefruit juice 6, this does not apply to amlodipine, which showed no such effect in controlled studies 2
Avoid unnecessarily restricting grapefruit consumption in patients on amlodipine, as this dietary restriction is not evidence-based for this specific medication 1, 2