Cau 36: trbay duoc dong hoc cua 3 glycosid tim: digitoxin, digoxin, uabain

1.Hap thu:

-Glycosid ko ion hoa , khuyech tan thu dong trong ong tieu hoa. thuoc cang tan trong lipid cang de khuyech tan. Cac nhom OH lam han che do tan trong lipid cua thuoc

+Digitoxin: 1 nhom OH -> de tan trong lipid, dc hap thu hoan toan = duong uong

+Digoxin: co 2 nhom OH -> hap thu kem Digitoxin nhung hon uabain

+Uabain: cu 5 nhum OH -> k hap thu qua tiou hoo, fai tiom tinh mach

2.Fon foi:

-Thuoc cang de tan trong lipid cang de gan vao protein huyet tuong: digitoxin 90% > digoxin 25% > uabain 0% xong k vung ben va de dang dc jai fong ra dang tu do

-Glycosid gan nhieu mu : tim, gan , foi, than vo nhung cquan này dc tuoi mau nhieu, voi tim thuoc gan theo kieu lket cong hoo tri (digitoxin, digoxin) uabain k lket theo kieu này -> k toch luy. Khi [K+] trong mau cao thuoc it gan vao co tim

-Qua dc hang rao rau thai

3.Chuyen hoo:

-Digitoxin chuyen hoo hoàn toàn o gan, digoxin 5%, uabain k chuyen hoo

-Cac pu qtronh:+lion hop: acid glucoronic 5%, H2SO4

+thuy fan mat dan fan duong

+hydroxyl hoo gentin

+Epime hoo: chuyen OH tu vi tro o -> o

4.Thai tru:

-Digitoxin, digoxin thai tru qua than va gan, o nhung noi do 1 fan thuoc dc tai hap thu => tag tich luy trong co the

-Uabain k bi chuyen hoo, thai tru qua than dung dich cun hoat tonh