Navigating the Grapefruit Dilemma and its Interaction with Drugs (A Case Study)

Overdose is one issue that is encountered in pharmacology, and I will discussing in today's post cases of overdose, and surprisingly, this overdose cannot be mentioned in the cases without mentioning Grapefruit.

A 42 year old woman was brought to the emergency unit after two weeks of migraine, nausea, and altered sensorium. The woman had a history of migraine but then her subsequent symptoms were worrisome. The woman has been taking Fioricet for her migraine symptoms, as well as Verapamil which is used to treat angina as well as migraine. When we reached the emergency room, she was not responsive with a complete heart block as electrical signals frome the top of the heart cannot reach the bottom. Not quite long, she went into respiratory failure and needed to be intubated after which she was placed on a ventilator.

Her blood work was taken for drug overdose and there was no sign of drug overdose except for the fact that her verapamil concentration was 5 times what it should normally be. After her recovery, it was seen that she has never overdosed on verapamil to a point of 5X. She said she only did a 2X on days were she mistakenly took an overdose and such day was the day she was rushed into the EU.

The woman although confirmed that she had been feeling nausea for a few days and have been taking grapefruit juice to help stop the feeling and she had been taking about 4 liters between the seven days of her admission to the EU. It was then clear that there was something in the Grapefruit that caused the increase in dose of the medication from a mistaken 2 dose to 5 dose.

Another case was a case of a woman who took Procardia for her blood pressure along with antidepressants and died after taking grapefruit for a while with the medication. Another man took Seldane and died after taking grapefruit for a while. So one thing is common with these people, and that's grapefruit.

Grape fruit intoxication didn't just start, scientists started to notice that something was wrong with grape fruit in 1998. They took 6 healthy men, and 6 men with hypertension and asked them to take drug to lower blood pressure with water, orange juice, and grapefruit. It was then seen that combining grapefruit with the medications led to 50% increase in headaches, facial flushing, and lightheadedness and the grapefruit had made the bioavailability (how much of the active ingredient)of the drug to increase 3x.

When Cytochrome P450 3A4 (CY3PA4) which metabolizes drug is being inhibited, causing drugs to get into the body without them being metabolized thereby causing a high concentration in the body so drugs that are supposed to be broken down and excreted will not be broken down and excreted. This is caused by a compound in grapefruit known as Furanocoumarins and this means that there will be a higher concentration of whatever chemical is in the bloodstream since they aren't broken down.

Grapefruit isn't the only suspect here, limes, and Seville oranges (sweet oranges do not have Furanocoumarins) and these fruits, juice or drinks that contain them taking 4 hours before any drug intake will give the effect of allowing the entire drug into the system without some of the drug being broken down and excreted thereby allowing 100% of the drug to be found in the blood. When taken 10 hours before medication, 50% of the drug is found in the bloodstream, and 25% when taken 24 hours before drugs.

In the symphony of drug interactions, Grapefruit emerges as a silent disruptor, altering medication dynamics in unexpected ways. Today's exploration unearths stories of unintentional overdoses, unveiling the intricate dance between Grapefruit and vital drug metabolism enzymes. As we bid adieu, let this serve as a reminder – knowledge is our shield against unseen perils. So, tread carefully, be mindful of your fruit companions, and ensure your medication journey stays on the right track. Stay informed, stay vigilant.

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Read More

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https://www.researchgate.net/publication/
https://buffalonews.com/news/grapefruit-interactions
https://pubmed.ncbi.nlm.nih.gov/1671113/
https://www.medscape.com/viewarticle/801822?form=fpf
https://www.merckmanuals.com/professional
https://sunrisehouse.com/addiction-info/path-drugs-take-body/
https://www.cmaj.ca/content/185/4/309
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1312247/
https://www.drugs.com/article/grapefruit-drug-interactions.html

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Image Reference

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Image 1 || Flickr || Colorful fruits and pills

Image 2 ||theindianpractitioner.com|| Diabetes drugs could save thousands of lives: UK Study