warnings and cautions
5 WARNINGS AND PRECAUTIONS Anaphylactic Shock and Serious Hypersensitivity Reactions have occurred. Monitor patients during and after completion of plerixafor administration. ( 5.1 ) Tumor Cell Mobilization in Leukemia Patients: plerixafor may mobilize leukemic cells and should not be used in leukemia patients. ( 5.2 ) Hematologic Effects: Increased circulating leukocytes and decreased platelet counts have been observed. Monitor blood cell counts and platelet counts during plerixafor use. ( 5.3 ) Potential for Tumor Cell Mobilization: Tumor cells may be released from marrow during HSC mobilization with plerixafor and filgrastim. Effect of reinfusion of tumor cells is unknown. ( 5.4 ) Splenic Rupture: Evaluate patients who report left upper abdominal and/or scapular or shoulder pain. ( 5.5 ) Embryo-Fetal Toxicity: Can cause fetal harm. Advise women not to become pregnant when taking plerixafor. ( 5.6 , 8.1 ) 5.1 Anaphylactic Shock and Hypersensitivity Reactions Serious hypersensitivity reactions, including anaphylactic-type reactions, some of which have been life-threatening with clinically significant hypotension and shock have occurred in patients receiving plerixafor [see Adverse Reactions (6.2) ] . Observe patients for signs and symptoms of hypersensitivity during and after plerixafor administration for at least 30 minutes and until clinically stable following completion of each administration. Only administer plerixafor when personnel and therapies are immediately available for the treatment of anaphylaxis and other hypersensitivity reactions. In clinical studies, mild or moderate allergic reactions occurred within approximately 30 minutes after plerixafor administration in less than 1% of patients [see Adverse Reactions (6.1) ] . 5.2 Tumor Cell Mobilization in Leukemia Patients For the purpose of HSC mobilization, plerixafor may cause mobilization of leukemic cells and subsequent contamination of the apheresis product. Therefore, plerixafor is not intended for HSC mobilization and harvest in patients with leukemia. 5.3 Hematologic Effects Leukocytosis Administration of plerixafor in conjunction with filgrastim increases circulating leukocytes as well as HSC populations. Monitor white blood cell counts during plerixafor use [see Adverse Reactions (6.1) ] . Thrombocytopenia Thrombocytopenia has been observed in patients receiving plerixafor. Monitor platelet counts in all patients who receive plerixafor and then undergo apheresis. 5.4 Potential for Tumor Cell Mobilization When plerixafor is used in combination with filgrastim for HSC mobilization‚ tumor cells may be released from the marrow and subsequently collected in the leukapheresis product. The effect of potential reinfusion of tumor cells has not been well-studied. 5.5 Splenic Enlargement and Rupture Higher absolute and relative spleen weights associated with extramedullary hematopoiesis were observed following prolonged (2 to 4 weeks) daily plerixafor SC administration in rats at doses approximately 4-fold higher than the recommended human dose based on body surface area. The effect of plerixafor on spleen size in patients was not specifically evaluated in clinical studies. Cases of splenic enlargement and/or rupture have been reported following the administration of plerixafor in conjunction with filgrastim. Evaluate individuals receiving plerixafor in combination with filgrastim who report left upper abdominal pain and/or scapular or shoulder pain for splenic integrity. 5.6 Embryo-Fetal Toxicity Based on findings from animal reproduction studies, plerixafor can cause fetal harm when administered to a pregnant woman. Plerixafor administration to pregnant rats during organogenesis resulted in embryo-fetal mortality, structural abnormalities, and alterations to growth at exposures approximately 10 times the exposure at the recommended human dose. Advise pregnant women of the potential risk to the fetus. Advise females of reproductive potential to use an effective form of contraception during treatment with plerixafor and for one week after the final dose [see Use in Specific Populations (8.1) ] .