Amid this summer’s sweltering temperatures, many people are finding relief by sipping fruity cocktails and smoothies or drinking fruit juices.
But a doctor is warning millions of people taking common medications such as statins and antidepressants that ingesting grapefruit — a common “healthy” ingredient in many summer snacks and drinks — can have serious consequences.
“Grapefruit is a pleasant snack for most, but it is important to disclose large amounts of grapefruit use to your doctor because it can interact with an array of medications,” Dr. Nicole James, a doctor based in Illinois, told news agency SWNS.
Common cocktails that contain grapefruit include palomas, greyhounds, some margaritas and sea breezes.
“Grapefruit contains natural compounds — primarily furanocoumarins and flavonoids. These inhibit an important enzyme called cytochrome P450 3A4,” James said.
This enzyme is referred to as CYP3A4.
It plays an important role in breaking down oral medications so that the body can properly process them.
“When you ingest grapefruit, it blocks this enzyme,” said James, who is also a clinical research fellow in the department of dermatology at Stanford University.
“This causes drugs that would normally be broken down in the gut wall to instead pass through intact, leading to significantly higher-than-intended blood levels of the medication,” James added.
Having higher concentrations of a medication than normal can cause serious side effects.
Drug concentrations in the blood can rise too fast and to dangerously high levels, Harvard Medical School also noted, as Fox News Digital previously reported.
“Patients taking statins could experience higher levels than normal, which can cause muscle breakdown and cramps,” James noted.
Meanwhile, patients taking certain blood pressure medications like amlodipine “may experience dizziness and low blood pressure.”
Sedatives can also pose a risk, with medications like midazolam being impacted by grapefruit and causing “extreme drowsiness and even slowed breathing,” she said.
Antidepressants like sertraline also come with a warning to avoid the fruit.
For those who think it would take a lot of grapefruit to have an effect — James said this isn’t the case.
“As little as one grapefruit or 200 mL of juice can cause a clinically relevant increase in medication concentrations, and the effect can last up to 72 hours because grapefruit irreversibly inactivates CYP3A4 enzyme,” she said.
People should keep an eye on mixed fruit juices, smoothies and cocktails, as grapefruit juice is a common ingredient, she said.
“If patients ingest a large amount of grapefruit while on these medications, they should monitor for any symptoms and avoid ingesting any more grapefruit,” said James, advising people to always seek medical attention if there are any concerns.
The doctor also warned about other ingredients that patients should be aware of — and reiterated that reaching out to healthcare professionals ahead of time is always a wise move.
Among the ingredients to watch:
- Vitamin K-containing ingredients such as leafy green vegetables or cranberry juice should be carefully considered by those taking warfarin, which is commonly prescribed for reducing the risk of heart attack and stroke.
- Dairy-containing products can reduce the effectiveness of certain antibiotics such as ciprofloxacin and bisphosphanates (often taken for osteoporosis prevention).
