Some meds react badly with grapefruit

DEAR DR. ROACH >> Some prescription medications have a warning they may have an interaction or reaction to grapefruit. Is it dangerous to continue to eat grapefruit even if you’re on meds, or is it an overreaction?

DEAR READER >> Grapefruits and grapefruit juice (and a few other less-common citrus fruits) inhibit one of the enzymes used by the liver to detoxify drugs, called CYP3A. This enzyme is used in metabolism of dozens of drugs. In most cases, it increases drug levels.

Often, this is not a big deal. Most of the drugs we use have low toxicity, and people tolerate a slightly higher blood level due to grapefruit. However, some drugs, especially those that work on heart rhythms (like amiodarone), immunosuppressants (including cyclosporine, tacrolimus and other related drugs), and chemotherapy, are at a high risk for a drug interaction with even one grapefruit or glass of juice daily. Your pharmacist can look up your prescription medications to tell you if there is a potentially dangerous interaction.

Gallbladder disease runs in my family. Two of my

DEAR DR. ROACH >>

grandparents, my mother and three of my four sisters, including me, have had gallbladders removed.

Several of us have had some lasting problems post-surgery — namely diarrhea. A friend recently told me that she has had success with the supplement choline. Is there any risk to taking it, and is there a safe dosage?

Choline is a supplement usually marketed to “help memory,” although there is not good evidence to support it. I have not seen choline marketed for treatment of post-surgery diarrhea.

I wonder if your friend might have confused two drugs with similar-sounding

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names, ones that I frequently recommend for diarrhea following gallbladder surgery: cholestyramine and colestipol.

The main job of the gallbladder is to hold and release bile acids, which help us properly break down and absorb fats. Without a gallbladder, bile acids are released continuously by the liver into the small intestine. Bile acids are reabsorbed at the end of the small bowel and reused. If too many bile acids go all the way through the small intestine into the colon, diarrhea occurs.

Most people’s small intestines are able to increase their absorption of bile acid within a few weeks or months after surgery. So the diarrhea does