Benzonatate
"Severely asthmatic for over 45 years.  When my pulmonologist who had been giving me cough syrup w codeine retired, the new doc suggested I try perles.  Been using them about 6 months.  I found them very helpful during an episode of flu.  I have had less spectacular results during allergy-related exacerbations.  

I find them useful at concerts, movies, lectures, which I had previously left due to asthma episodes.  

I find they work best for me if I take them 3x a day (i.e. for prevention) during allergy season, or an exacerbation.  At other times, they are part of the various meds available to handle situations. Doc said OK to take  6 in 24 hrs when needed. Cheaper than many asthma Rx

I scored them 7 on the 10 scale for effectiveness"