Many drug interactions are the resu

Many drug interactions are the result of an alteration of CYP450 metabolism.10 The non- sedating antihistamines terfenadine (Seldane) and astemizole (Hismanal), and the gastro- intestinal motility agent cisapride (Propul- sid), were all withdrawn from the U.S. market because metabolic inhibition by other drugs led to life-threatening arrhythmias.11 The calcium channel blocker mibefradil (Posicor) was with- drawn from the U.S. market in 1998 because it was a potent enzyme inhibitor that resulted in toxic levels of other cardiovascular drugs.12
Drugs interact with the CYP450 system in several ways. Drugs may be metabolized by only one CYP450 enzyme (e.g., meto- prolol by CYP2D6) or by multiple enzymes
(e.g., warfarin [Coumadin] by CYP1A2, CYP2D6, and CYP3A4).13 Drugs that cause CYP450 metabolic drug interactions are referred to as either inhibitors or induc- ers (Table 110,14-16). Inhibitors block the metabolic activity of one or more CYP450 enzymes. The extent to which an inhibitor affects the metabolism of a drug depends upon factors such as the dose and the ability of the inhibitor to bind to the enzyme. For instance, sertraline (Zoloft) is considered a mild inhibitor of CYP2D6 at a dose of 50 mg, but if the dose is increased to 200 mg, it becomes a potent inhibitor.17 Inhibitory effects usually occur immediately.
Additionally, a drug can be both metab- olized by and inhibit the same enzyme (e.g., erythromycin), or it can be metabolized by one enzyme and inhibit another enzyme (e.g., terbinafine [Lamisil]).18 Drugs may be intentionally combined to take advantage of CYP450 inhibition. Ritonavir (Norvir), a protease inhibitor and potent CYP3A4 inhibitor, is added to lopinavir (Kaletra) to boost serum levels in patients with human immunodeficiency virus.14

Kết quả (Việt) 1:

Many drug interactions are the result of an alteration of CYP450 metabolism.10 The non- sedating antihistamines terfenadine (Seldane) and astemizole (Hismanal), and the gastro- intestinal motility agent cisapride (Propul- sid), were all withdrawn from the U.S. market because metabolic inhibition by other drugs led to life-threatening arrhythmias.11 The calcium channel blocker mibefradil (Posicor) was with- drawn from the U.S. market in 1998 because it was a potent enzyme inhibitor that resulted in toxic levels of other cardiovascular drugs.12Drugs interact with the CYP450 system in several ways. Drugs may be metabolized by only one CYP450 enzyme (e.g., meto- prolol by CYP2D6) or by multiple enzymes(e.g., warfarin [Coumadin] by CYP1A2, CYP2D6, and CYP3A4).13 Drugs that cause CYP450 metabolic drug interactions are referred to as either inhibitors or induc- ers (Table 110,14-16). Inhibitors block the metabolic activity of one or more CYP450 enzymes. The extent to which an inhibitor affects the metabolism of a drug depends upon factors such as the dose and the ability of the inhibitor to bind to the enzyme. For instance, sertraline (Zoloft) is considered a mild inhibitor of CYP2D6 at a dose of 50 mg, but if the dose is increased to 200 mg, it becomes a potent inhibitor.17 Inhibitory effects usually occur immediately.Ngoài ra, một loại thuốc có thể là cả hai metab olized bởi và ức chế enzyme tương tự (ví dụ như erythromycin), hoặc nó có thể được chuyển hóa bởi một enzym và ức chế một enzym (ví dụ như, terbinafine [Lamisil]).18 thuốc có thể kết hợp cố ý để tận dụng lợi thế của sự ức chế CYP450. Ritonavir (Norvir), một chất ức chế protease và chất ức chế mạnh CYP3A4, được thêm vào lopinavir (Kaletra) để tăng nồng độ huyết thanh ở bệnh nhân suy giảm miễn dịch của con người virus.14