More than 40 drugs should not be combined with grapefruit

Before starting a treatment with new drug check how he reacts with citrus!

BEFORE you begin to drink a new drug for lowering blood pressure, depression, psychosis, angina pectoris, increased blood cholesterol, arrhythmia, epilepsy or cancer, read the instructions if could it be taken in combination with grapefruit. Because it was found that this fruit, either as fruit juice or jam, may cause interactions with more than 40 drugs!

Side effects may be due to medication but also a result of drug interactions, experts warn. As more drug is taken, the greater the risk of side effects and interactions.


– The largest number of drugs and / or substances which are taken up in the liver is metabolized by a so-called microsomal liver enzymes – explains Professor Dr. Milica Prostran, specialist in clinical pharmacology, Pharmacotherapy Faculty of Medicine, University of Belgrade, a member of the Special Working Group on the rational use of antibiotics Ministry of Health of the Republic of Serbia. – Enzymes are protein structure, and can inhibit or stimulate or induce. The main enzyme is CYP3A4, which participates in the metabolism – biotransformation up to 70 percent of all drugs and substances.

Grapefruit juice inhibites CYP1A2, and CYP3A4 enzyme. Bio-flavonoid, naringenin and furanokumarin dihidrobergamotin are key ingredients of this fruit that inhibit mikrozomne liver enzymes.

– Enzyme inhibition is the most common mechanism of drug interactions and depends on the dose of drug / substance inhibitors – said Dr. Prostran. – The competition takes place at the active site of the enzyme. Comes to an increase in the plasma concentration of drugs whose metabolism of these enzymes are involved, it is theoretically possible to gain their pharmacological response, including the appearance of their side effects.

So, if someone takes the antiarrhythmic “amiodarone” and drinks a liter or more of grapefruit juice a day may be associated with serious heart arrhythmias. Taking a large volume of juice from this fruit a few days before taking “verapamil” can lead to cardiac arrest.

– Rhabdomyolysis or pain in skeletal muscle can occur when with “Simvastatin” you eat the whole fruit, once a day for two weeks – emphasizes our interlocutor. – Taking jams of grapefruit, and 1,500 grams in one week before the beginning of ‘tacrolimus’, can result in nephrotoxicity, if the patient is also taking this immunosuppressive drug.WDOwGnH

It does not matter what grapefruit we take – the whole piece of fruit, juice, jam, notes Dr. Milica Prostran – it is essential that these are large amounts or volumes. Neither the time factor, or the length of the intake, should not be ignored.

– It is believed that for two cups, or about 400 ml juice can lead to inhibition of the enzyme – indicates Dr. Prostran. Each summary and instructions for the drug that is in the package, there is described the possible interaction of a prescribed drug with the fruit.

In moderation

With taking grapefruit in combination with certain medications you should be careful, but it does not mean that by all costs you should remove it form the diet, experts say.

– Grapefruit can be taken in moderation – says Professor Milica Prostran. – And should definitely tell your doctor about eating habits.