Top 10 Weirdest Prescription Drug Side Effects

Weird Side Effect 7: Colored Urine

I wouldn't taste the rainbow if I were you.
I wouldn't taste the rainbow if I were you.
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Rainbow urination might sound kind of cool. But in some cases, if your urine is any color other than clear, yellow or yellowish-orange, you could have something seriously wrong with you. Very dark orange, reddish or brown urine, for example, probably has blood in it and could indicate an infection. Some prescription drugs, though, can turn your urine different colors just by virtue of passing through your system. Red urine can also be caused by taking drugs such as phenazopyridine, used to treat urinary tract infection pain, or deferoxamine, used to treat iron poisoning.

Here are some other potential urine colors and some of the drugs that can cause them:

  • Black - can result from taking Flagyl (generic name metronidazole), furazolidone and several other antibiotics. Aldomet (generic name methyldopa), used to treat high blood pressure in pregnant women, can make urine appear to be black because it darkens upon contact with bleach -- often used to clean toilet bowls.
  • Purple - can be a side effect of taking phenolphthalein, used for a long time as a laxative but falling out of favor due to concerns that it may cause cancer [source: Melville].
  • Green - can result from taking Elavil (generic name amitriptyline hydrochloride), an antidepressant also used to treat bed-wetting in children, or Robaxin (generic name methocarbamol), a muscle relaxant used to treat muscle spasms.
  • Blue - can be a side effect of taking Dyrenium (generic name tariamterene), a diuretic, or methylene blue, a chemical compound used in medications like Urised to help reduce irritation caused by bladder infections.

We assure you, the side effect listed on the next page is really there.