Yesterday ProfG was talking about lemon verbena today, I want to move the debate onto grapefruit
What has this got to do with nutriceuticals? Well Prof G was saying we don't know what they will do and so we can't advise that people take them. Whilst we may perceive nutriceuticals do no harm cause they seem harmless....I would argue if they have no side effects as immunomodulators, they are probably at too low a dose to be useful becuase if they were any good they would have sie effects,because you can't have one without the other
You say mushroom food, but what can the humble grapefruit do?
Well it can interact with a number of drugs. There is a suggestion that grapefruit juice can release a number of compounds that are
inhibitors of the cytochrome P450 CYP3A4 enzyme, which can affect the metabolism of a variety of drugs, increasing their bioavailability by blocking their metabolism/breakdown.
When drugs are taken orally, they enter the gut to be absorbed in the small intestine and sometimes, in the stomach. In order for drugs to be absorbed, they must pass through the cells that line the intestine wall before they can enter the liver (hepatic portal) circulation to be distributed in the blood circulation. Drugs are metabolized by drug-specific metabolizing enzymes. Metabolizing enzymes transform these drugs into metabolites. The primary purpose for drug metabolism is to detoxify, inactivate, solubilize and eliminate these drugs. As a result, the amount of the drug in its original form that reaches systemic circulation is reduced due to this first-pass metabolism. Compounds within Grapefruit juice can inhibit these enzymes.
So by eating grapefruit your therapeutic drug may become dangerous.
A number of pharmaceutical drugs can induce these enzymes such that they can make the contraceptive pill useless. Carbamazepine is an anti-epilepsy drug and you have to slowly give more and more of it because it induces enzymes which break the drug down. Eventually you saturate the system to the drug becomes consistently active.
This is in part why we are using Oxcarbazepine in the PROXIMUS trial, as it is less likely to be broken down than some of the other sodium channel blockers.
Are you considering entering the clinical trial if not why not? or are you waiting until the results of the optic neuritis phenytonin study are known to see if it stops nerve loss like the animal studies suggest it will.
I can say in the beasties Oxcarbazepine was much more active than phenytonin, but that phenytoin was used because it does not cause its own breakdown like say carbamazepine. The trial is finished and the results are being analysed and maybe ready for presentation in a couple of months...Fingers crossed.
The question with all nutriceuticals is how much grapefruit do you need to target the biology, you are interested in?
This is why ProfG is not going to say take Lemon verbena, because without the extra knowledge it can be bad advice.
Labels: Drug interactions