DEAR DR. ROACH: I am a 73-year-old male and have been diagnosed with a number of different medical conditions. I have one kidney (stage 4) and have had atrial fibrillation since 2008. Recently my nephrologist said I have high potassium levels. In order to treat this, he has prescribed a medicine called Veltassa. I started on it and my numbers are fine, but the problem is I cannot afford the medicine at $1,100 per month. According to my doctor, the only alternative med is Kayexalate, which he doesn’t want to use and which gave me serious diarrhea during a hospital stay. Are you aware of something else that can help me? — S.C.

ANSWER: High potassium levels are a serious problem in severe kidney disease. Without the kidney, the body has no way to effectively get rid of potassium, so as kidney failure progresses to end stage (called stage 5, where a kidney transplant or dialysis becomes life-sustaining), potassium becomes extremely important. Reducing potassium intake is critical, and I am sure your nephrologist (“nephros” is Greek for “kidney”) has given you advice on reducing high potassium foods, such as orange juice, bananas, potato skins, avocados and many others. Very careful adherence to a low potassium diet will reduce the amount of medication you need. A dietitian nutritionist can help.

Unfortunately, you can’t avoid potassium entirely, so if medicines like furosemide (Lasix), which make the kidney excrete more potassium, haven’t worked, you need an alternative. High blood potassium levels are very dangerous. They can predispose the heart to life-threatening rhythm disturbances, for which prompt, effective treatment is needed.

The colon contents normally have high levels of potassium. Patiromer (Veltassa), sodium zirconium cyclosilicate (Lokelma) and sodium polystyrene sulfonate (a discontinued brand name was called Kayexalate) all are substances that avidly bind potassium chemically, but they are prepared already bonded with a different ion. It’s calcium in the case of Veltassa, and sodium in the case of Lokelma and Kayexalate. In the colon, the potassium binds to the medication in exchange for the other positive ion. Both Veltassa and Kayexalate also contain sorbitol, which often causes diarrhea, which helps bring potassium levels down faster.

Veltassa ($818 per month on Goodrx.com) and Lokelma ($673 per month) are quite expensive; however, generic Kayexalate, despite being a bit less expensive, is not a recommended treatment due to its increased risk of intestinal ulceration and perforation.

Since Lokelma is less costly, you might ask your nephrologist about it. Otherwise, keep a very careful diet. Only a kidney transplant or dialysis will definitively treat the high potassium.

DEAR DR. ROACH: I have seen advertising for magnetic bracelets. Does wearing magnets really do anything for your health? — G.T.

ANSWER: Numerous studies have been done, but there is no convincing evidence that magnets are any better than placebo for wrist pain, back pain or hip and knee arthritis. However, the placebo response is powerful. If you really believe that a placebo — which might be a medication, a wearable magnet or surgery — is going to help with symptoms, it often does help. This happens as much as a third of the time. There are no side effects from wearing a magnet, but you should keep powerful magnets away from your credit cards.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.