I'm using Reactine (different brand name in US, I think) right now and there seems to be not too much problem with adverse reactions or reduction of effectiveness of AAS, but I find that after a few weeks these antiallergy drugs make you tired and give you libido problems. Then you know it's time to stop even if you have to sneeze all over your naked wife.
Sorry to hear a placebo-like drug like Claritin is not available OTC in the US. No great loss!
There was actually a great article in the New York Times advising New York State residents to drive to Canada, buy a year's supply of Reactine or Claritin OTC, and use the money they save to have a great weekend holiday in Toronto, Montreal or Ottawa.
These drugs aren't nearly as effective as Seldane was. It's banned now. Apparently very bad on the liver. Oh well, so what's that now, 6 strikes against my liver.
gtaman: shilling for the Canadian tourism industry since 2001