What Causes Itchy Rashes While On Duromine?

Hi I started 30mg Duromine yesterday and have developed an itchy rash overnight after only one tablet. Should I just ride it out and take an antihistamine and see if it settles down? or should I stop taking it altogether.I know some side affects disappear or settle after a few days.I really don't want to stop taking it as I desperately need to lose weight and have exhausted other avenues.