Changes in Serum Concentration of Antidepressants After Bariatric Surgery and Recommendations for Postbariatric Surgery Antidepressant Therapy.

BACKGROUND: Bariatric surgery affects the absorption of medications including antidepressants, but data regarding these effects are limited. OBJECTIVES: Our objectives were to review publicly available data regarding changes in antidepressant serum concentration following bariatric surgery in order to develop medication dosing recommendations in this patient population. METHODS: A comprehensive literature review was performed utilizing key search terms in Pubmed. Additional data were retrieved from the Food and Drug Administration and DrugBank Online resources. RESULTS: A total of twelve published articles were included in addition to the publicly available data from the Food and Drug Administration and DrugBank. The serum concentration of antidepressants following bariatric surgery demonstrated considerable variability between and within drug classes due to unique pharmacokinetic features, drug preparation, and formulation. Recommendations were developed from published data regarding changes in serum concentration and drug-specific pharmacokinetic data. CONCLUSIONS: To our knowledge, this is the first study to propose medication dose-adjustment recommendations for patients on antidepressants undergoing bariatric surgery. We were limited by the relatively small amount of data available and recommend monitoring patients and use of clinical judgment along with this guidance.

Recruitment of osteoclast precursors by stromal cell derived factor-1 (SDF-1) in giant cell tumor of bone.

Giant cell tumor (GCT) of bone is a unique bone lesion that is characterized by an excessive number of multinucleated osteoclasts. GCT consists of neoplastic stromal cells, multinucleated osteoclasts and their precursors, thus serving as a naturally occurring human disease model for the study of osteoclastogenesis. It still remains unclear how stromal cells of GCT recruit osteoclast precursors. In the present study, we characterized the cellular components of GCT and confirmed the presence of CD14(+)-monocytes/CD68(+)-macrophages and CD34(+)-hematopoetic stem cells that express CXCR4, a specific receptor for SDF-1; SDF-1 gene expression and presence of SDF-1 protein were confirmed by real time RT-PCR, in situ hybridization, and immunohistochemistry in the GCT tissue and cultured cells. SDF-1 was present at 25-50 ng/ml in the conditioned media from the GCT cultures, which is in the range of physiological chemotactic concentration. Migration of osteoclast precursors was 2.5-fold higher in response to GCT conditioned media compared to the control media; and migration was inhibited by an average of 36% with anti-SDF-1 neutralizing antibody or competing recombinant SDF-1. These results suggest that SDF-1 is one of the significant chemoattractant factors involved in the recruitment of hematopoietic osteoclast precursor cells during tumor-induced osteoclastogenesis.