what body system is used for nafcillin
Be the first to review this Drug. Nafcillin is an antibiotic in the penicillin group of drugs. It fights bacteria in your body. Nafcillin is used to treat many different types of infections, especially those caused by staphylococcus bacteria (staph infections).Nafcillin may also be used for other purposes not listed in this medication guide.afcillin Interactions. Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, stop taking nafcillin and call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.