Filgrastim generally is well tolerated, and very rarely produces adverse effects so severe that discontinuation is required. The adverse effect reported most frequently is mild to moderate (occasionally severe) medullary bone pain. The bone pain appears to be dependent on the dose and/or route of administration (lower incidence with subcutaneous injection, and higher with intravenous). The safety profile reveals Filgrastim (ReliGrast) to be well tolerated with no significant adverse reactions observed. The most common adverse events were pyrexia, vomiting, diarrhea, asthenia, generalized pain, cough, abdominal pain, anemia, pain in extremity, nausea, anorexia, hypoaesthesia, paraesthesia, mucosal inflammation and dysuria, all of these being chemotherapy emergent and not treatment related. Most adverse events were of mild severity requiring no hospitalization or medication. The incidence of bone pain was also low, with only two patients complaining of severe bone pain.