Peginterferon-alpha-2b

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[B]Twice-Weekly Peginterferon-alpha-2b Best in Chronic Hepatitis C Genotype 1 [/B]

By Laurie Barclay, MD
Medscape Medical News


Aug. 4, 2003 — Peginterferon-alpha-2b must be given twice weekly in chronic hepatitis C genotype 1 to maintain continuous drug exposure and viral clearance, according to the results of a kinetic study published in the August issue of the Journal of Viral Hepatitis.

"The serum concentration of peginterferon-alpha-2b decreases exponentially with almost undetectable levels on days 6 and 7 after dosing," write E. Formann and colleagues from the University of Vienna in Austria. "Thus, the decrease in interferon concentration may result in the rebound of viral levels in blood."

Ten patients with chronic hepatitis C who had never received interferon were randomized to four weeks of treatment with 1.0 µg/kg peginterferon-alpha-2b once or twice weekly. Blood concentrations of peginterferon-alpha-2b peaked 24 hours after the first dose, with a subsequent linear decline.

Once-weekly dosing was associated with undetectable levels of peginterferon-alpha-2b in nine patients on the sixth day after treatment. With twice-weekly dosing, peginterferon-alpha-2b at any given time point was detectable and higher than with once-weekly dosing (P between .01 and .0001).

In all patients, viral load decreased within two days after the first dose and increased on day 3. With once-weekly dosing, it increased further until day 7, but with twice-weekly dosing, it decreased again on day 4 and remained lower until study termination (P < .001).

"To achieve continuous drug exposure and to improve initial viral clearance, peginterferon-alpha-2b has to be given at least two times weekly," the authors write. "Whether twice-weekly dosing will improve the results of combination therapy in patients with HCV genotype 1 has yet to be determined."

      2003年8月4日--根據一項發表於8月號Journal of Viral Hepatitis的研究結果顯示，基因型1慢性C型肝炎患者必須每週服用Peginterferon-alpha-2b兩次，以維持連續的劑量和病毒的清除效果。
　　
　　奧地利維也納大學的E.Formann表示，在服用後6-7日，peginterferon-alpha-2b 的血清濃度幾乎降至無法檢測的含量，因此，干擾素濃度的減少會導致病毒數量回升。
　　
　　十名患有慢性C型肝炎而未曾接受干擾素治療的患者隨機分配至每週服用peginterferon-alpha-2b 1.0μg/kg一次及二次的組，一共進行四個星期的治療，在服藥後24小時的劑量達到高峰，但是之後便線性降低。
　　
　　每星期服用一次劑量的患者，在服藥第六天後，血液中的peginterferon-alpha-2b便降低致無法檢測的含量，每星期服用二次的患者在任何時間點測得的peginterferon-alpha-2b 含量均高於每星期服用一次（P介於.01 和 .0001 之間）。
　　
　　在所有患者中，在服用第一次劑量後的前二天，病毒量均減少，但是在第三天開始增加，在第七天時進一步增加，但是每星期服用兩次劑量的患者，在第四日時再度減少，並且維持低病毒量直到研究結束（P < .001）。
　　
　　為了維持體內的藥物含量、改善病毒的清除率，必須每週服用peginterferon-alpha-2b至少二次，每週服用兩次對於HCV基因型1的患者之合併治療是否有效果，還需要進一步研究