Antibiotics, no matter the stregth, can cause nausea and/or vomiting.  One thing is that the capsule may disolve in the stomach. There are some that do not start to breakdown until they are in the small or large intestines.  Antibiotics can break down the cillia in your body. Look at your tongue. Do you see the little pieces sticking up? That kind of tissue runs through every tract in your body. Antibiotics, along with the illness itself, can irritate or remove them completely. That is how you get thrush mouth or other yeast infections as a result.  Drink a small amount of milk or a piece of chocolate a little bit before taking them. This coats your stomach lining.  Do not drink orange juice (any citrus) or cola with the meds.  Applesauce, yogurt, or cottage cheese is good to take it with.  It is not abnormal to do this when you take antibiotics.  Stopping or decreasing the med only hurts your body. you have to have a steady stream of the med for it to work. Skipping or dropping a pill makes you have to start all over and the med may not be as effective as it is needed when you are done with the last dose.