When I was given antibiotics for fever by my doctor, I noticed that my urine is unusually yellow. Why is that?

  • 2
    Any chance you were also given a drug called Pyridium to treat symptoms of a urinary tract infection?
    – Susan
    Apr 18, 2015 at 23:40
  • 1
    @Susan negative. It was for fever and cold. I recall I was diagnosed with some kind of respiratory infection. I did not experience symptoms of urinary tract infection.
    – kathy
    Apr 19, 2015 at 6:07
  • 3
    OK, thanks. It would be really helpful if you could tell us what antibiotic it was.
    – Susan
    Apr 20, 2015 at 1:49
  • 1
    Your medicine came with a package insert. It might mention urine color changes. (This is the medical equivalent of saying "read the documentation.") Jul 12, 2015 at 5:55

2 Answers 2


The color, odor and consistency of urine can be differ and can reveal what you've been eating, how much drinking and what diseases you have, so change of the color is usually something completely normal. All substances circulating in your body (including bacteria, yeast, excess protein/sugar can make their way there. It's an important part of your body's disposal process and it's useful tool of diagnosis.

Tomas Griebling, MD, MPH (vice chair of the urology department at the University of Kansas) says:

From a historical view, urinalysis was one of the original windows into what's happening in the body.

Anthony Smith, MD (professor and chief of urology at the University of New Mexico) says:

The urine is there primarily to get rid of toxins or things that would otherwise build up in the body that would be bad for the body.

Urine gets it color from the urochrome pigment and it ranges between light straw/yellow and dark/deep amber (honey). Darker color is normally when you're urinating first in the morning (this indicates your liver was busy at night to get rid of toxins). During day or evening can indicate dehydration, so you should drink more water.

These are some of the medicines and vitamins that can change the colour of urine:

  • Yellow or yellow-green: cascara, sulfasalazine, the B vitamins.
  • Orange: rifampicin, sulfasalazine, the B vitamins, vitamin C.
  • Pink or red: phenolphthalein, propofol, rifampicin, laxatives containing senna.
  • Green or blue: amitriptyline, cimetidine, indomethacin, promethazine, propofol, triamterene, several multi-vitamins.
  • Brown or brownish-black: levodopa, metronidazole, nitrofurantoin, some anti-malarial agents, methyldopa, laxatives containing cascara or senna.

Source: Urinary Incontinence health centre

If you worry about your urine color (apart of contacting your doctor of course), you may purchase urine test strips for determination of leukocytes, nitrite, urobilinogen, protein, pH, blood, specific gravity, ketone, bilirubin and glucose in urine. You can easily check if your infection is gone or not.

See the following chart (The Color of Pee) found at Cleveland Clinic:

The Color of Pee: Pale straw, Transparent Yellow, Dark yellow, Amber of honey, Syrup, Pink, Orange, Blue, Green, Foaming or fizzing

See also PDF version of it.

See also:

  • 5
    "there's no such thing as purple urine" ... shucks! lol +1 good post
    – user147
    Apr 6, 2015 at 5:09

The anti-biotic could possibly be having an antidiuretic effect. This reduces the amount of water in urine, and so the natural yellow hue is intensified.

There is a definition of an antidiuretic at Wikipedia. The key element of the body's natural ability to retain urine is Vasopressin.

There are natural remedies for both urine retention and lack of urine retention. Try:


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