The drug in the article called furosemide can also be called Lasix. This drug helps to remove water being retained in the body and can also remove nutrients in the process. Many people on large doses of Lasix have been known to start having leg cramps due to a loss of potassium.
If you are on the drug Lasix there are many sources of potassium and you should easily find a way to work potassium into your diet. There are more ways to get potassium than just eating a bunch of bananas. As always you should consult your doctor before any major change in your diet.