<prompt> Answer this question truthfullyWhat information is available on Nafcillin Sodium Injection?  <response>: <reason> Nafcillin may cause side effects. Tell your health care provider if either of these symptoms is severe or does not go away:upset stomach diarrheaIf you experience any of the following symptoms, call your health care provider immediately:rash itching fever chills facial swelling wheezing difficulty breathing unusual bleeding or bruising dizziness seizures sore mouth or throatIf you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administrations FDA MedWatch Adverse Event Reporting program online at or by phone 1-800-332-1088. 