Pharm: Chemo

Question 1

1. What are steroids used for in the treatment of brain metastases?
2. Anticonvulsants?

Answer 1

1. Tx brain edema

2. Tx seizures

Question 2

What is the definitive Tx for brain metastases?

Answer 2

1. surgery

2. whole brain radiation

Question 3

What is the role of chemo in brain metastases?

Answer 3

lack of evidence to support conventional chemo

can’t cross BBB

Question 4

temozolomide

Answer 4

oral
methylates DNA: O6 guanine bases
crosses BBB
pro-drug
Tx: astrocytoma, glioblastoma multiforme
off label Tx: malignant glioma, malignant melanoma
AE: myelosuppression
teratogen
resistance: MGMT

Question 5

Mechanism of resistance to chemo that are unique to the brain

Answer 5

gap junctions between astrocytes and tumor cells: interrupt apoptosis

Question 6

methyl guanine methyl transferase (MGMT)

Answer 6

suicide repair enzyme that accepts methyl group

TEMOZOLOMIDE resistance

Question 7

nitrosoureas

Answer 7

DNA alkylator
cross BBB
Tx: malignant glioma
cross resistance with other alkylators unlikely
AE: myelosuppression; PULMONARY FIBROSIS, ENDOCRINE dysfunction; ENCEPHALOPATHY; SEIZURE

Question 8

carmustine: BCNU

Answer 8

parenteral
nitrosourea
decomposition products: carbamolyate proteins and inhibit DNA repair
Tx: astrocytoma, brain metastases, medulloblastoma

Question 9

lomustine: CCNU

Answer 9

oral

nitrosourea

Question 10

carmustine wafer

Answer 10

biodegradable disc implanted in brain cavity after Sx

Tx: high grade glioma

Question 11

convection enhanced delivery

Answer 11

local infusion of chemo with catheter into tumor and surrounding area

Question 12

chemo fog

Answer 12

peripheral TNF-a accesses the brain and causes long term cognitive impairment
occurs even in chemo that does not cross BBB