17 August, 2011
Does Grapefruit Interfere With Amlodipine?
Grapefruit contains chemicals that can interfere with the enzymes that your body uses to break down certain medications. When this happens, the amounts of medication in your body can build up and cause serious side effects. Amlodipine is one of the medications that might be affected by grapefruit juice.
Amlodipine, sold under the brand name Norvasc, is a type of medication called a calcium-channel blocker. Doctors prescribe amlodipine for people with high blood pressure to help lower the risk of heart attack and chest pain by opening up your blood vessels to improve blood flow. Along with taking amlodipine, you will need to make dietary and lifestyle changes.
Grapefruit and Amlodipine
Many calcium channel blockers, including nicardipine, nifedipine and verapimil, interact with grapefruit juice unpredictably. Amlodipine also interacts with grapefruit, but in a very small way, not affecting either blood pressure or heart rate, according to a study published in 1996 in the "European Journal of Clinical Pharmacology." However, you still should be careful not to consume large amounts of grapefruit juice as different people react differently to medications.
Drinking large amounts of grapefruit juice might make side effects from taking amlodipine more likely. Possible side effects include allergic reactions, drowsiness, dizziness, headache, flushing, stomach pain, swollen hands and feet, chest pain, nausea, irregular heartbeat and sweating. Speak with your doctor if you experience troubling side effects, as you might need your medication or dosage changed.
Just because the interaction between grapefruit and amlodipine does not appear to cause significant clinical side effects doesn't mean you should ignore it, according to an article published in the "British Journal of Clinical Pharmacology" in April 2002. The amount of amlodipine absorbed by different people varies, so it is possible that drinking large amounts of grapefruit juice could have a significant effect in some people. However, consuming small amounts of grapefruit juice is likely safe.
- MayoClinic.com; Grapefruit Juice: Beware of Dangerous Medication Interactions; Katherine Zeratsky, R.D., L.D.; November 2009
- Drugs.com: Amlodipine
- "British Journal of Clinical Pharmacology"; Amlodipine and Grapefruit Juice; M. Josefsson and J. Ahlner; April 2002
- "The Independent"; A Question of Health: Slap and Tingle; Fred Kavalier; September 2002
- "European Journal of Clinical Pharmacology"; Effect of Grapefruit Juice on the Pharmacokinetics of Amlodipine in Healthy Volunteers; M. Josefsson, et al.; 1996
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