G-CSF serum pharmacokinetics during peripheral blood progenitor cell mobilization: neutrophil count-adjusted dosage might potentially improve mobilization and be more cost-effective.

The optimal dosing schedule of G-CSF for peripheral blood progenitor cell (PBPC) mobilization is still under investigation although many centers use 10 microg/kg/day in a single subcutaneous dose. However, G-CSF clearance increases with increasing absolute neutrophil count (ANC). Hence a G-CSF dosage adjusted to ANC might be a reasonable approach. We measured G-CSF trough serum levels by sandwich ELISA assay at different ANCs in eight patients undergoing treatment with filgrastim at 10 microg/kg/day in a single subcutaneous dose. A total of 26 samples were analyzed, and a strong correlation between increasing ANC and decreasing G-CSF levels was found by linear regression analysis (P < 0.0003, r2 = 0.4199). For ANC values above 5000/microl the trough serum levels, ie 24 h after administration, were consistently below the level that provides maximal clonogenic precursor stimulation in vitro (10 ng/ml). Serial serum G-CSF measurements performed in three patients at 0, 3, 6, 9 and 24 h after G-CSF administration, showed a reduction of the area under the curve (AUC) with increasing ANC. For an ANC of 20000/microl or greater, the G-CSF serum level fell under the maximal in vitro stimulation threshold of 10 ng/ml within 12 h. This preliminary pharmacokinetic data seems to suggest that an ANC-adjusted G-CSF dosing schedule might improve the design of PBPC mobilization regimens.

Comparison of two application techniques of EMLA and pain assessment in pediatric oncology patients.

BACKGROUND AND OBJECTIVES: The study was designed to compare the analgesic efficacy of the local anesthetic EMLA when applied as a patch and as a cream in combination with a Tegaderm dressing to pediatric oncology patients undergoing repeated lumbar punctures. METHODS: The analgesic effect of the two products was assessed by a continuous or discrete visual analog scale in 24 children 3-16 years old, during two lumbar punctures. Distress was rated by use of the Observational Scale of Behavioral Distress. RESULTS: No significant differences were found between the pain and distress scores for the different preparations of EMLA. CONCLUSION: The EMLA patch and the EMLA cream are equally effective in alleviating pain associated with lumbar puncture. The EMLA patch simplifies and speeds up the application of EMLA. It also allows for control of the dose administered per application, thus preventing both over- and underdosing.