Grapefruit is a highly nutritious fruit, but many people believe that you should not consume it if you are taking medications. Some medications clearly mention it on the label that you should avoid grapefruit while you are using those medications. Should you be taking those warnings seriously?

Will Grapefruit Interact with Medications?

Yes, it is possible to experience side effects of combining grapefruit and medications. The reason is that grapefruit contains certain chemicals that affect the way your body metabolizes many medicines in the liver or intestine.

To get a better idea, you need to understand how your body breaks down drugs for eventual elimination. Your body tries to metabolize toxins or drugs for easy elimination, but grapefruit juice can affect the process. It decreases the activity of an enzyme called the cytochrome P4503A4 or simply CYP3A4. The enzyme plays a big role in the process of breaking down toxins and drugs. Grapefruit juice can actually block the enzymes completely mainly because it contains furanocoumarins. With the enzyme's ability to break down drugs decreasing, the levels of certain toxins or drugs may increase in your blood, which can lead to an increased risk of experiencing new side effects.

Will Taking Medications at Different Times Reduce Interactions?

Some people say you can combine grapefruit and medications, so long as you do not take them simultaneously. Unfortunately, that is not true because the interaction may still happen even when you consume your medications and grapefruit juice at different times.

That happens because your body experiences the effects of grapefruit juice for 24 hours or longer, which is why it can still interact with medications that you have to take daily. It is therefore a better idea to avoid grapefruit juice for the entire treatment period. 

Do All Medicines Interact with Grapefruit?

No, that is not the case. However, many commonly prescribed medicines may interact with grapefruit juice. Some of the most common examples include the medicines used to treat or deal with:

• Hypertension: Nifedipine, felodipine, nisoldipine, and nimodipine
• High Cholesterol: Lovastatin, atorvastatin, and simvastatin
• Heart Arrhythmia: Amiodarone
• Anxiety Disorders and Depression: Sertraline and buspirone
• Organ Transplants: Tacrolimus and cyclosporine
• Erectile Dysfunction: Sildenafil
• Allergies: Fexofenadine

In case you are not sure about how the medicines you take may interact with grapefruit, be sure to talk to your pharmacist or healthcare provider.

Specific Examples of Medications That Can Interact with Grapefruit

When it comes to grapefruit and medications, you have to know some specific medications that can interact with grapefruit.

1. Amiodarone

Grapefruit affects the amount of amiodarone your body can absorb. It enables your body to absorb more than necessary. That is the reason why you might experience different side effects. Never consume grapefruit when you are on amiodarone.

2. Atorvastatin

Used for lowering cholesterol, atorvastatin can interact with grapefruit juice and make it difficult for your body to break down the medication required for high cholesterol. It is important to mention that grapefruit does not interact with all of the medications used for the treatment of high cholesterol, and you can still drink grapefruit juice when taking fluvastatin, rosuvastatin, or pravastatin.

3. Buspirone

Major interaction might take place when combining grapefruit juice and buspirone together. The combination might increase the side effects associated with the medication.

4. Cyclosporine

Drinking grapefruit juice while taking this medication might increase the amount of cyclosporine your body absorbs. This might lead to an increased risk of experiencing serious side effects.

5. Medications Moved by Pumps in Cells

You have to use pumps to move certain medications to cells. Grapefruit juice could change the way these pumps work. It might also affect the amount of medications your body absorbs. This might decrease the effectiveness of these medications. Some of the most common medications in this category include bosentan, fexofenadine, etoposide, glyburide, celiprolol, methotrexate, irinotecan, talinolol, and rifampin.

6. Medications for High Blood Pressure

Combining grapefruit with high blood pressure medications might increase the amount of medication your body absorbs. You might end up noticing your blood pressure going too low. It is therefore better to avoid grapefruit if you are already taking medications for hypertension. Some common examples of medications used to treat high blood pressure include verapamil, nifedipine, felodipine, isradipine, diltiazem, and amlodipine.

7. Medications Changed by the Liver

To receive the effects of certain medications, your liver first need to break them down and that is when grapefruit juice can cause problems. Your liver might take longer to process certain medications if you are also drinking grapefruit at the same time. This might change the effects and side effects of some medications. Be sure to talk to your doctor before drinking grapefruit juice if you are already taking medications changed by the liver. Some common examples of such medications include fexofenadine, ketoconazole, lovastatin, triazolam and others.

8. Sildenafil

Grapefruit and medications can interact with each other, and sildenafil is another example of those medications. Your body has to break down sildenafil to eliminate it from your system. It might take longer to complete the process if you are drinking grapefruit juice at the same time. This might also make side effects rather serious.