dexamethasone in brain tumor

 Q: Why dexamethasone is a drug of choice to decrease vasogenic edema from primary and metastatic brain tumors?

Answer: The objective of this question is to highlight the fact that dexamethasone doesn't only work through its anti-inflammatory effect but also has direct mechanisms to reduce tumor-induced edema. It works via various direct mechanisms:

• it upregulates Ang-1, a strong blood-brain barrier-stabilizing factor. Brain tumor tends to disrupt the blood-brain barrier.
• it downregulates vascular endothelial growth factor (VEGF) - a strong permeabilizing factor, in astrocytes and pericytes. 
• it is found to inhibit the production of interleukin 1 from tumor-associated macrophages in glioblastoma models.

#oncology

#pharmacology

References:

1. Kim H, Lee JM, Park JS, et al. Dexamethasone coordinately regulates angiopoietin-1 and VEGF: a mechanism of glucocorticoid-induced stabilization of blood-brain barrier. Biochem Biophys Res Commun 2008; 372:243. 

2. Herting CJ, Chen Z, Maximov V, et al. Tumour-associated macrophage-derived interleukin-1 mediates glioblastoma-associated cerebral oedema. Brain 2019; 142:3834.