asthma
"I have taken Singulair or the generic Montelukast for almost 2 decades now and have had excellent results on the drug. I almost cannot tell I have asthma while taking the medication, provided I am not exposed to cigarette, wildfire, or any other form of smoke.  However, I want to share that I have had the experience now of taking three U.S. generics that I did not have excellent results on.  Within about 30 days of starting the generic in each case, I began experiencing asthma symptoms as if I were taking either a placebo or nothing at all.  Only one generic that I have found thus far has been as effective for me as the brand name medication, and the generic has unfortunately been discontinued by my pharmacy."