I checked this out for you because I was not familiar with that name, As it turns out, it is another name for Acetaminophen, best known by the brand name Tylenol.
As such, it may be providing symptomatic relief in lowering a fever and giving mild to moderate pain relief.
It will have no effect on the cause or progress of your cold or flu. Any perceived benefit would be a placebo effect.
That getting better eventually is all your natural immune system doing it's job of being awesome!
I'm not sure what your doctor told you, but there are safety concerns, particularly in its toxicity to the liver if too much is taken. An adult should take no more than 4 grams a day, less if you have any sort of liver dysfunction. There are concerns even this amount is too much in the elderly. You should not drink alcohol while using it.
When taking over the counter medications, it is important to check the ingredients in each of them, As many contain acetaminophen but only mention it in the fine print. Taking several cold/flu medications with different names but the same ingredient has causes people trouble in the past,
