A reaction to a medication usually occurs within a couple of hours of ingestion. From then on it's often the usual - bit of tummy upset, slightly looser stools etc. Make sure you have a probiotic yogurt each day and keep hydrated. other than that you have to let the drug do it's work. I'm on a 4 week course of Ofloxacin and a few weeks into it I stupidly read about the side effects. It doesn't do you any good to worry about what if's. If you have taken the tablet(s) already today and you're ok (apart from feeling anxious) then you won't be allergic to these meds.

Ed