Are there certain foods I should avoid while taking amlodipine?

The package insert for Norvasc, one brand of amlodipine, mentions no food restrictions while taking amlodipine.¹ The same insert mentions that taking 240 mL of grapefruit juice a day did not affect the pharmacokinetics of amlodipine. The bioavailability of amlodipine is thought to be unaffected by food.²

A 1989 study of 12 healthy white volunteers found that food did not significantly influence bioavailability of amlodipine.³ ECG variables, blood pressure, and heart rate among study participants were also not affected in any significant way.

A Swedish study evaluated the effect of drinking moderate amounts of grapefruit juice while taking amlodipine.⁴ Grapefruit juice seems to increase the bioavailability of amlodipine, but this small study of healthy volunteers found no significant effect on heart rate or blood pressure. The effect of large amounts of grapefruit juice, however, cannot be ruled out.

As amlodipine is sometimes given in combination with other blood pressure medication or lipid lowering medication, the effects of food on these combination drugs has also been studied.

An in vitro simulation of drug metabolism of amlodipine and atorvastatin (a lipid-lowering drug) in fed versus fasted states was conducted to model intestinal absorption.⁶ The simulation found that less atorvastatin was absorbed in the fed state.

^References

1. Norvasc [package insert]. Kirkland, Quebec: Pfizer Labs; 2016.
2. Ananchenko G, Novakovic J, Lewis J. Amlodipine besylate. Profiles Drug Subst Excip Relat Methodol 2012; 37 (1): 32-72.
3. Faulkner J, Hayden M, Chasseaud L, Taylor T. Absorption of amlodipine unaffected by food. Solid dose equivalent to solution dose. Arzneimittelforschung 1989; 39 (7): 799-801.
4. Josefsson M, Zackrisson A, Ahlner J. Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers. Eur J Clin Pharmacol 1996; 51 (2): 189-193.
5. Lv C, Wei C, Wang X, et al. The influence of food on the pharmacokinetics of amlodipine and losartan after single-dose of its compound tablets in healthy Chinese subjects. Drug Res (Stuttg) 2014; 64 (5): 229-235.
6. Dennison TJ, Smith JC, Badhan RK, Mohammed AR. Fixed-dose combination orally disintegrating tablets to treat cardiovascular disease: formulation, in vitro characterization and physiologically based pharmacokinetic modeling to assess bioavailability. Drug Des Devel Ther 2017; 11 : 811-826.