Drug Interactions between filgrastim and topotecan

Although filgrastim is prescribed to help boost the levels of white blood cells in patients undergoing chemotherapy, using it during or too soon after completion of a cycle of topotecan can sometimes have negative effects by prolonging the period during which your white blood cell counts remain low. This can make you more vulnerable to infections. In general, filgrastim works best when given at least 24 hours after finishing a course of topotecan. Talk to your doctor or pharmacist if you have any questions or concerns. Contact your doctor if you develop signs and symptoms of infection such as fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination. There is also some evidence that use of filgrastim may increase the risk of a serious lung disorder that can occasionally develop during treatment with topotecan. You should seek immediate medical attention if you experience cough, fever, difficulty breathing, wheezing, and/or pale or bluish skin discoloration. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.