HI, I WOULD ADVISE TO TRY ADVIL OR MOTRIN FOR INFANTS.. ITS THE SAME AS PEOPLE WITH CF AN ADVIL HAS A ANTINFLAMAORTY IN IT THAT HELPS WITH TIGHTNESS, SWELLING. SO IF YOUR SON HAS A COLD AND IS CONGESTED TRY MOTRIN, I SWEAR BY IT IT WILL HELP KEEP EVERYTHING OPEN SO THE CONGESTION CAN BREAK UP AND GET OUT.. I GIVE THAT TO MY SON WHO IS 3 AND NOT CF, BECAUSE I TAKE IT AND HAVE CF.. IT WORKS FOR BOTH OF US...TTYLNOL JUST HELPS PAIN AND FEVERS DOES NOTHING ELSE, THE ADVIL OR MOTRIN HAS THE ANTINFLAMATORY DRUG IN IT TOO..