Patented in 1967, Cefadroxil has indeed been effective in treating bacteria responsible for causing tonsillitis, and infections of the skin and urinary tract. In addition, it is used as an antibiotic prophylaxis before dental procedures, for patients allergic to penicillins. Before taking this medication, tell your doctor if you are allergic to any drugs (especially penicillin). Also tell him/her if you have kidney disease or a history of intestinal problems. It is worth noting that antibiotic medicines, such as Cefadroxil, can cause diarrhea, which may be a sign of a new infection. So, if you have diarrhea that is watery or has blood in it, call your doctor immediately. You should also call him/her at once if you have any of the following side effects: fever, chills, body aches, seizure, pale or yellowish skin, increased thirst and loss of appetite. Bear in mind that Cefadroxil can be taken on an empty stomach or with food or milk if it causes an upset stomach. Plus, this medication is not expected to be harmful to an unborn baby. However, you should tell your doctor if you are pregnant or plan to become pregnant during treatment, especially since Cefadroxil may pass into breast milk and could harm a nursing baby