asthma
"I was on Singulair for about a year, when my medical aid would all of a sudden only pay for Tropaz (I believe it is a generic). Tropaz was equally effective, but after about six months of use I developed terribly dry and burning lips. I went of Tropaz for about six months, and started using it again. My lips were fine and for a couple of months I had no side-effects. The medical aid then changed from Tropaz to Minair and within 2 two months I had a disastrous allergen of hives and welts."