wtf with the ignorance in this thread
HCTZ is one of the most common prescribed blood pressure medications (in the USA at least) because it is off patent and dirt cheap and side effects are well known after being around so long.
It's one of the few on Walmart's $4/month prescription list for people without insurance. I had to use it for a year or two when at first they wouldn't do my dental work at the dental school because my BP tested too high.
It does make you pee a lot, so maybe that is why it is abused. I couldn't take the full pill, would make me get up like three times a night, so took half instead.
Once I started running again full time after the dental work my BP dropped enough to stop taking it entirely. Had no idea it was banned but I'm not even remotely good enough to worry about such things.
It is most definitely not performance enhancing, if anything, ALL bp medication has detrimental effects on endurance athletes, and there are plenty of very good runners who have to take bp medication, it is a genetic condition.