Do you know whether there are some foods you should avoid while you are taking your medicine? The classic example is grapefruit. When its ability to interact with medications was first discovered, many health professionals were skeptical. Now, some tell patients not to eat grapefruit at all when they are taking certain prescription drugs. Is there a happy medium?
Can You Safely Eat Grapefruit While Taking Simvastatin?
Q. I love grapefruit, the whole fruit. I used to eat grapefruit often, but I have gone without it for several years now. That is because I take simvastatin to lower my cholesterol.
I discussed my cravings with my heart doctor and we reached a happy medium. I can have half a grapefruit in the morning every five or six days. I take my pill in the evening, and he figures 12 hours or so is a safe time spread between medication and fruit.
Is Breakfast to Bedtime Enough Time?
A. Your doctor has it partially correct. Grapefruit contains compounds (furanocoumarins) that inhibit a crucial enzyme in the digestive tract that breaks down many medications, including simvastatin. This means more medicine circulates in the body, increasing the risk for side effects. The enzyme, called CYP3A4, is responsible for the metabolism of numerous medications in addition to simvastatin.
When grapefruit and simvastatin are taken together, blood levels of the drug increase by 260 percent (Lee, Morris & Wald, American Journal of Medicine, Jan. 2016). When taken 12 hours apart, as your doctor recommends, blood levels go up by 90 percent.
Enjoying grapefruit once or twice a week probably won’t have a lasting effect. Daily grapefruit, however, could cause trouble since the grapefruit effect lasts at least 24 hours. Just to complicate the situation, some people react far more strongly when they eat grapefruit than others do. We don’t yet have good ways to tell ahead of time who will get a very noticeable boost in blood levels from this interaction.