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Health issues with grapefruit?

My sister has received a half case of grapefruit. She was told by her doctor to avoid grapefruit due to drug interactions. She was wondering if she could use the juice for a marinade that is then cooked. Also could she eat candied grapefruit rind? TIA.

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  1. My understanding is that any sort of grapefruit can cause an adverse interaction in certain drugs. She should ask her pharmacist or doctor, though.

    1. a web search turns up this information, but checking with your physician is the best advice when it comes to health matters:


      1. She should definitely avoid grapefruit if she is on a statin drug such as Lipitor or Zocor.

        3 Replies
        1. re: Jeff C.

          My father has been on Lipitor for many years. His doctor told him he could have a grapefruit 10 -12 hours before/after taking his Lipitor. Since he prefers having the grapefruit with his evening meal, he takes Lipitor in the morning. I am quite sure there are many people on Lipitor who should avoid eating grapefruit.

          I understand that grapefruit can interfere with other kinds of medication as well.

          1. re: Jeff C.

            Or avoid the statins and eat the grapefruit.

            1. re: Jeff C.

              It's not just statins... grapefruits have a unique chemical composition that affects a LOT of medications including anti-depressants and various other psychotropic medications. She'd be best off to get rid of the grapefruit and not take a risk.

            2. Until cleared with her dr for the specific meds she is on she needs to avoid the grapefruit raw/cooked/juiced etc and follow his advice for her specfic regimin.

              1. I too read about this some time ago and have avoided grapefruit since I'm on meds.

                But what about other citrus fruits?

                I'm thinking about pomelos and tangelos which may be/are related by hybridisation.

                3 Replies
                1. re: DockPotato

                  Since both grapefruit and tangelos are hybrids of pommelos, I would ask the doctor who prescribed the medications before consuming either variety of citrus.

                  1. re: John E.

                    Aye, that's my intention on my next visit. Avoidance till then.

                    I'm more concerned about folks who may not be aware.

                    1. re: DockPotato

                      What is mildly interesting about my father's situation is that he has a ruby red grapefruit tree at his winter home in Arizona. (He also has two orange and two lemon trees.)

                2. <She was told by her doctor to avoid grapefruit due to drug interactions.>

                  This is absolutely true for certain drugs. I don't know what drug she is on, but grapefruit interferes with CYP3A4, so if her drugs depend on CYP3A4, then it is a major problem.

                  I can go into a bit if you like. Basically, all pharma drugs have a projected pharmacokinetic profile, such as Cmax, clearance and half time. In short, we make some assumptions of how the drug get eliminated overtime from your body. Here is a typical oral PK profile:


                  Different drugs depend on different mechanisms and enzymes for elimination.

                  CYP3A4 is a major enzyme for drug elimination for many drugs, and grapefruit can interfere CYP3A4.

                  What does this mean in simple term?

                  It means that a major elimination pathway will be blocked (due to grapefruit), and now the drug concentration will be much higher than originally expected. If you look at the above graph, you can now imagine the gray area size doubled or tripled or even more. The area will surpass that "MTC" line -- the minimal toxic concentration.

                  In short, you will OVERDOSE, and reach toxic level -- as if you took 2 times, 3 times, 4 times.... amount of the recommended doses. You didn't actually take more drugs, but the end result is the same.

                  <She was wondering if she could use the juice for a marinade that is then cooked. Also could she eat candied grapefruit rind?>

                  A definite no for juice -- assuming she is taking a drug which can be affected by grapefruit. I have no idea what she is taking.

                  Not sure about grind, but I won't risk it until more is known.

                  We are not talking minor side effects here. There are numerous cases where people died because of grapefruits.