Should I Avoid Grapefruit With My Medication?

How does grapefruit interact with medications?

Medications are processed in your liver and small intestine by a specialized group of proteins called cytochrome P450 (CYPs).

CYPs break down medications, reducing their concentration in the blood.

Grapefruit and a few of its close relatives, such as Seville oranges, tangelos, pomelos, and Minneolas, contain a class of chemicals called furanocoumarins.

Furanocoumarins impair the way CYPs break down medications in the gut and liver, meaning that dangerous levels of a drug can build up in your blood. This can increase the risk of side effects.

The amount of grapefruit it takes to disrupt medications depends on the person, the drug, and the dose. As there’s no safe amount, it’s best to avoid grapefruit altogether if your doctor or the drug manufacturer recommends it.

At-a-glance: Drugs with grapefruit interactions

The table below lists medications that grapefruit interacts with. The following sections explain the interactions in more detail.

Drugs that grapefruit interacts with

Cholesterol medications

Some cholesterol medications called statins are affected by grapefruit.

Statins work by limiting the natural production of cholesterol. This improves the profile of lipoproteins in the blood and decreases deaths from heart disease in patients at risk of it.

Statins can cause rhabdomyolysis, or the breakdown of muscle tissue. This leads to muscle weakness, pain, and occasionally kidney damage.

Grapefruit increases the blood levels of the following common statins, increasing the risk of rhabdomyolysis:

• atorvastatin (Lipitor)
• lovastatin (Mevacor)
• simvastatin (Zocor)

Statins that grapefruit does not interact with include:

• pravastatin (Pravachol)
• rosuvastatin (Crestor)
• fluvastatin (Lescol)

Blood pressure medications

Most types of blood pressure medications are not affected by grapefruit.

However, grapefruit can interact with the following blood pressure medications, so it’s best to avoid consuming it:

• felodipine (Plendil)
• nifedipine (Procardia)
• losartan (Cozaar)
• eplerenone (Inspra)

The first two medications in this list are calcium channel blockers. They work by altering how your blood vessels use calcium, relaxing the vessels and lowering blood pressure.

The last two medications in this list work by decreasing the activity of a hormone called angiotensin 2, which naturally increases blood pressure.

Losartan is unusual in that grapefruit decreases its effects, which might make it less effective at controlling blood pressure.

Eplerenone works similarly to losartan, but its levels increase when taken with grapefruit. Excessive eplerenone levels can cause too much potassium in the blood, which can interfere with heart rhythm.

Alternative blood pressure medications include:

• spironolactone (Aldactone)
• amlodipine (Norvasc)

Heart rhythm medications

Grapefruit influences a few medications that treat abnormal heart rhythms.

These interactions can be particularly dangerous and include:

• amiodarone
• dronedarone (Multaq)

These two medications play a critical role in managing the health of people with heart rhythm disorders. Grapefruit-related changes in levels of these drugs can cause dangerous heart rhythm changes.

Anti-infection medications

Collectively called antimicrobials, these anti-infection medications vary widely in their actions and breakdown in the body.

Although antimicrobials are one of the most diverse categories of medications, only the following are known to interact with grapefruit:

• erythromycin
• rilpivirine and related HIV drugs
• primaquine and related antimalarial drugs
• albendazole

Erythromycin is used to treat several types of bacterial infections. Excess levels of this medication can disrupt heart rhythm.

Grapefruit also increases levels of the HIV medications rilpivirine and maraviroc, in addition to primaquine-related antimalarial drugs. This may affect heart rhythm or function.

Possible alternative antimicrobials include:

• Clarithromycin: This medication is in the same class as erythromycin, which does not interact with grapefruit.
• Doxycycline: This is both an antibiotic and an antimalarial drug and does not interact with grapefruit.

Mood medications

Most antidepressants and anti-anxiety drugs are safe to use with grapefruit.

However, the following medications do interact with grapefruit, including:

• quetiapine (Seroquel)
• lurasidone (Latuda)
• ziprasidone (Geodon)
• buspirone (Buspar)
• diazepam (Valium)
• midazolam (Nayzilam)
• triazolam (Halcion)

Drugs like quetiapine and lurasidone are used to treat mood and behavioral disorders. Increased levels of these drugs can cause changes in heart rhythm or sleepiness.

Diazepam, midazolam, and triazolam are sedatives that are sometimes used for panic attacks or other forms of anxiety.

Blood thinner medications

Blood thinners are used to treat or prevent blood clots. Some of them are affected by grapefruit, including:

• apixaban (Eliquis)
• rivaroxaban (Xarelto)
• clopidogrel (Plavix)
• ticagrelor (Brilinta)

Clopidogrel depends on CYPs (the proteins that grapefruit limits) to work. Thus, it becomes less active when mixed with grapefruit.

Contrarily, grapefruit increases the blood levels of other medications on this list, which can result in bleeding.

Warfarin (Coumadin) is a possible alternative used for purposes similar to those of apixaban and rivaroxaban. While warfarin is sensitive to foods containing vitamin K, its activation is not affected by grapefruit.

Pain medications

The following pain medications are affected by grapefruit:

• fentanyl (Duragesic)
• oxycodone
• colchicine

Fentanyl and oxycodone are narcotic pain relievers. Although their blood levels are only slightly affected by small amounts of grapefruit, it may change the length of time they remain in the body.

Colchicine is an older medication used to treat gout. It’s processed by CYPs and could interact with grapefruit.

Possible alternatives that are not affected by grapefruit include:

• morphine
• hydromorphone hydrochloride (Dilaudid)

Erectile dysfunction and prostate medications

The following erectile dysfunction (ED) and prostate medications may interact with grapefruit:

• sildenafil (Viagra)
• tadalafil (Cialis)
• tamsulosin (Flomax)
• silodosin (Rapaflo)

ED medications like sildenafil and tadalafil work by relaxing blood vessels, which increases blood flow to an erection.

Because other blood vessels relax with these medications as well, increased blood levels of these drugs caused by grapefruit can decrease blood pressure.

Moreover, prostate enlargement medications such as tamsulosin can also cause increased dizziness and low blood pressure when taken with grapefruit.

Alternative medications that are not affected by grapefruit include:

• finasteride
• dutasteride

The bottom line

Grapefruit interferes with proteins in the small intestine and liver that normally break down many medications.

Eating grapefruit or drinking grapefruit juice while taking these medications can lead to higher levels of them in your blood—and more side effects.

With some drugs, even small amounts of grapefruit can cause severe side effects, so it’s best to avoid combining them.

If you’re currently taking medications with grapefruit interactions, switch to an alternative drug or stop consuming grapefruit.

If in doubt, reach out to your doctor or pharmacist for personalized advice.