IMO, drugs can effect everyone differently. For example, I believe one drug I take, Bupropion (Welbutrin), in many cases, the recommended dose established during clinical trials was recommended to be 300 mg but that dose made me anxious, unable to sleep, etc. I am now taking 100 mg per day and don't notice any side effects. If you have any reactions or side effects, let your doctor know right away so that they can stop, adjust the dose, or whatever they think will help.