Can eating grapefruit while on antidepressants cause a fatal overdose? Probably not: Grapefruit can increase, or in some cases decrease, the effect of dozens of prescription and over-the-counter drugs. However, only a few antidepressants are recognized for interacting with grapefruit, and those interactions are not known to cause fatalities.
Since grapefruit season is coming up soon, this is a friendly reminder that you CANNOT eat grapefruit if you're on antidepressants. It can cause a fatal overdose.
This is what the post looked like on Facebook on December 16, 2021:
(Source: Facebook screenshot taken on Thu Dec 16 16:38 2021 UTC)
Grapefruit Interactions with Various Medications
A study published in 1991 found that grapefruit juice interacts with a few medications. Since that study, more research published in 2013 showed that grapefruit interacts with a wide variety of medications, and over 40 of those drugs were identified as having the potential to interact with grapefruit in a way that may cause severe adverse effects.
The U.S. Food and Drug Administration (FDA) explains why grapefruit may cause adverse effects on the body while on medications:
Many drugs are broken down (metabolized) with the help of a vital enzyme called CYP3A4 in the small intestine. Grapefruit juice can block the action of intestinal CYP3A4, so instead of being metabolized, more of the drug enters the blood and stays in the body longer. The result: too much drug in your body.
The amount of the CYP3A4 enzyme in the intestine varies from person to person. Some people have a lot of this enzyme and others just a little. So grapefruit juice may affect people differently even when they take the same drug.
Grapefruit may have the opposite effect on other drugs. Citing FDA pharmacology expert Shiew-Mei Huang, the resource says:
Why this opposite effect? Instead of changing metabolism, grapefruit juice can affect proteins in the body known as drug transporters, some of which help move a drug into our cells for absorption. As a result, less of the drug enters the blood and the drug may not work as well, Huang says.
The FDA identifies several drugs that may be affected by grapefruit consumption, including statin drugs to lower cholesterol, some antihistamines and some anti-anxiety drugs.
In the same resource, the FDA suggests that although the severity of the effects of grapefruit on certain drugs are unique to each person, general steps can be taken to determine whether grapefruit consumption is safe while on any drug. Some of those tips include consulting with one's doctor and reading the drug facts label or the patient information sheet included with the medication. The agency also warns that if a medication interacts with grapefruit, those who take that medication should also avoid consuming tangelos, Seville oranges and pomelos.
Grapefruit Interactions with Antidepressants
Information about how grapefruit specifically affects antidepressants does not point to fatalities. Lead Stories reached out to David Bailey, the lead researcher of the 1991 and 2013 studies that detailed interactions between grapefruit consumption and certain medications, for more information about the claim. In an email sent on December 16, 2021, Bailey told us he just finished updating a resource for the Canadian Pharmacists Association that lists the drugs affected by grapefruit. He continued:
This list includes more than 100 medications of which only 3 are antidepressants (fluvoxamine, sertraline, vilazodone) and none of them are likely to cause a life-threatening interaction with this fruit.
However, there are some antipsychotics (lurasidone, pimozide, quetiapine, ziprasidone) where an interaction with grapefruit has the possibility of causing a life-threatening cardiac arrhythmia and sudden death.
Similarly, in an email to Lead Stories on December 16, 2021, Mary Paine, a professor in the pharmaceutical sciences department at Washington State University, said:
I am not aware of a fatal interaction between grapefruit juice and any anti-depressant. Note that there are numerous anti-depressants. Some may interact with grapefruit juice depending on how they are metabolized (broken down).
Paine went on to say that she was skeptical of fatal grapefruit interactions with antidepressants.
Lead Stories reached out to the FDA for more information about the specific relationship between grapefruit and antidepressants. We will update this story with any relevant response.
TruthOrFiction.com published a fact check of this claim and labelled the claim "Decontextualized." Lead Stories also determined that based on the available information about the relationship between grapefruit and antidepressants, the claim appears overblown.