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Thuoc chua hen phe quan

Hen phe quan (HPQ) la mot benh ly duong ho hap hay gap va dang co chieu huong tang manh, tro thanh mot trong nhung benh khong nhiem trung pho bien nhat hien nay.

Phe quan cua nguoi bi hen (tren) va phe quan cua nguoi binh thuong (duoi).

Theo so lieu cua To chuc Kiem soat hen toan cau, do hien tuong o nhiem moi truong ngay cang tram trong, tan suat benh hen cung dang tang nhanh, dao dong tu 10-25% dan chung o cac nuoc phat trien va tu 8-20% tai cac nuoc dang phat trien. Tai Hoa Ky, nguoi ta thay tu 5-10% tre em bi HPQ va hang nam co den hon 500.000 tre phai nhap vien vi con HPQ nang, trong do hon 4.000 tre tu vong do con hen ac tinh du dieu kien kham chua benh o trinh do cao. O Viet Nam, theo mot so chuyen gia ve benh hen, ty le nguoi mac benh co the len toi 10-15% dan so.

HPQ la benh man tinh co tung dot kich phat, cap tinh nang nhu con HPQ gay kho tho dot ngot nang lam ngan can sinh hoat hay cong viec, lam giam chat luong cuoc song, tham chi gay tu vong dot ngot do con HPQ ac tinh (status asthmaticus) hay bien chung tu vong do tran khi long nguc dot ngot va du doi.

HPQ la mot benh di ung bieu hien tai duong ho hap, chu yeu la tai cac phe quan nho do cac yeu to gay benh xam nhap vao co the qua duong ho hap (di nguyen duong tho) gay cac ton thuong viem man tinh dac trung theo co che di ung  tai duong dan khi thap (cac phe quan gan tui khi) nhu: tang sinh cac tuyen nhay, tang sinh cac co tron tai duong ho hap duoi, phu ne quanh duong dan khi thap. Hau qua la gay co that co tron phe quan, viem va phu ne cac phe quan nho, tang xuat tiet va u dong cac chat nhay quanh dinh. Hau qua cuoi cung la giam luong khi luu thong toi phoi ma chu yeu do tac nghen cac phe quan nho o thi tho ra, lam ket khi chua nhieu than khi tu mau ra phoi khong duoc thai ra ngoai, dong thoi cung can tro luong khi chua nhieu o-xy tu ngoai vao phoi. Nhu vay, viec dieu tri benh HPQ doi hoi phai co hieu biet toan dien ve cac co che gay benh cung nhu cac roi loan thu phat de dieu tri nguyen nhan va xu tri thich hop.

Dieu tri HPQ gom 3 khau co ban: phat hien va loai tru hoac tranh tiep xuc voi tac nhan gay di ung (di nguyen) va khong che cac yeu to thuan loi phat sinh con hen; khong che va dan dan loai bo qua trinh viem man tinh tai duong dan khi thap (cac tieu phe quan); lap lai su luu thong cua duong dan khi bang cach giai quyet cac hau qua viem phu ne, xuat tiet dich quanh va co that he thong phe quan nho.

Cac thuoc dieu tri HPQ

Cac thuoc dung trong dieu tri HPQ bao gom 2 nhom chinh: nhom khong che va loai bo qua trinh viem do co che di ung va cac thuoc dung de lap lai su luu thong cua duong dan khi bang cach chong co that he thong phe quan nho.

Trong nhom cac thuoc chong viem, hien nay pho bien nhat la cac che pham corticoid. Cac thuoc nay dieu hoa viec giai phong cac hoat chat trung gian gay viem cac cytokin (hay con goi la interleukin) de giam su loi keo bach cau ai toan va cac te bao mast la loai san sinh nhieu chat trung gian mien dich IgE la chat lam tang cuong va duy tri phan ung viem. Ngoai ra, corticoid con co kha nang lam tang do nhay cam va so luong cac thu the beta 2 (b2 receptors) nen co tac dung gian tiep lam gian phe quan. Trong lam sang thuong su dung corticoid duong toan than nhu cortancyl, prednison,  prednisolon, solumedrol (uong hoac tiem lieu cao tu 2-10mg/kg/24 gio) de khong che con hen, nhat la con hen nang va hen ac tinh. De giam qua trinh viem di ung tai duong ho hap nham phong con hen tai phat, truoc day nguoi ta phai dung corticoid duong uong lieu thap. Nhung vi thuoc nay gay tac dung phu quan trong anh huong den su phat trien, chat luong cuoc song va giam suc de khang cua co the, nhat la khi phai dung keo dai va o tre nho. Nhung nam gan day, nguoi ta da san xuat duoc cac che pham corticoid dang hit don thuan nhu beclomethason dipropionat (becotid), budessonid (pulmicort), fluticason (flexotid) hay phoi hop nhu ventid (gom becotid va salbutamol) hoac seretid (fluticason va salbutamol). Cac thuoc nay chu yeu tac dung tai duong ho hap do khong hoac rat it tham vao mau nho cau truc dac biet va phan tu lon cua thuoc vi vay khong gay cac tac dung phu toan than dang ke, cho phep su dung lau dai, an toan, hieu qua cao. Tac dung phu chu yeu cua cac thuoc nay la nhip tim nhanh, run tay chan, ha kali mau va tang duong mau.

Ngoai ra, hien nay trong dieu tri hen, nguoi ta bat dau chu y den cac thuoc chong viem khong phai corticoid. Cac thuoc nay cung co tac dung ngan can qua trinh viem tai phe quan bang cach uc che te bao sinh chat gay viem nhu cromoglycate (lomudal), nedocromil (tilade), cac thuoc uc che thu the histamin H1 va uc che yeu to hoat hoa tieu cau nhu ketotifen (zaditen), hoac cac thuoc uc che truc tiep yeu to hoat hoa tieu cau nhu singulair. Cac thuoc nay khong co tac dung phu dang ke. Tuy nhien, nhuoc diem lon nhat cua chung la gia thanh cao.

Cac thuoc dung de lap lai su luu thong cua duong dan khi bang cach chong co that he thong phe quan nho gom 3 nhom chinh sau:

Nhom 1 gom cac thuoc kich thich thu the b2 (lam tang tong hop AMP vong, gay gian phe quan) bao gom cac thuoc chu yeu dung trong dieu tri cat con hen nhu: terbutalin (bricanyl) dang uong (vien, xi-ro) hoac tiem bap, tiem truyen tinh mach va albuterol (ventolin, salbutamol) dang uong (vien, xi-ro) hoac tiem truyen tinh mach.

Nhom 2 gom cac thuoc nhom methyl xanthin (theophylin va aminophylin) gay gian phe quan manh do uc che di hoa MP vong qua co che uc che men phosphodiesteras. Theophylin it tan trong nuoc nen chi dung o dang uong. Aminophylin tan trong nuoc nen co the tiem tinh mach phu hop voi cac tinh huong cap cuu, nhung can lieu cao hon (1mg aminophylin tuong duong 0,85mg theophylin). Cac thuoc nay co gioi han an toan dieu tri thap, de co tac dung phu nhu nhip tim nhanh, dau dau, co giat, nhat la khi phoi hop voi khang sinh thuoc nhom macrolid.

Nhom 3 la cac thuoc lam gian phe quan do uc che guanosin mono-phosphat vong (GMPc) nhu cac thuoc thuoc nhom khang cholin don thuan nhu oxitropium bromure (tersigat) hay ipratropium bromure (atrovent) hoac phoi hop voi cac thuoc kich thich thu the b2 nhu bronchodual (gom fenoterol va ipratropium). Nhuoc diem lon nhat cua cac thuoc nay la lam kho mieng va kich thich hong.

Tren day la cac nhom thuoc su dung trong dieu tri HPQ noi chung. Tuy nhien, viec su dung thuoc nao va  phoi hop cac thuoc ra sao con phu thuoc vao lua tuoi, tinh trang lam sang cua benh nhan (con nhe hay nang hay con hen ac tinh), muc dich dieu tri (du phong hay cat con).

TS.BS. Nguyen Van Bang