Bronch-aid iirc is ephedrine, not fentanyl. Fent is most definitely not available over the counter. Ephedrine and pseudoephedrine are amphetamine precursors, which produce a much different effect on the user than opioids, i.e. a stimulant vs a depressant. Definitely still not super healthy, but fentanyl is crazy concentrated and inhibits respiration (breathing) especially which is what makes it so easy to overdose. Not even sure what the equivalent dose of ephedrine is to a hit of meth, but I'd imagine unless your relative is downing like a bottle at a time, he's probably not getting very much of a high at all.