美国FDA批准了一种治疗成人慢性乙肝的新型药物Tyzeka（telbivudine）。慢性乙肝是一种严重的病毒感染，攻击肝脏并导致终身感染，可能进一步发展为肝硬化，最终导致肝癌、肝功能衰竭和死亡。Tyzeka是一种新分子实体，此前从未被批准在美国以任何形式进行营销。

研究人员在1367名慢性乙肝患者中，进行了为期一年的Tyzeka国际临床试验，该药最终在2006年10月获得批准。此次国际临床实验中四分之三的患者为男性，所有患者的年龄均在16岁以上（包括16岁）。研究结果表明：Tyzeka具有抗病毒效果，包括抑制乙型肝炎病毒的复制、改善肝脏炎症损伤等（与拉米夫定进行比较；拉米夫定是治疗慢性乙肝的五大药物之一）。

乙肝病毒主要通过血液传播，有时亦可通过性接触和输送被感染的血液来传播。Tyzeka 并不能治愈乙型肝炎，它的长期疗效也不清楚。

临床研究中关于Tyzeka副作用的报道大部分都为轻度至中度的，最常见的有肌酐磷酸激酶升高（CPK，这种酶存在于肌组织中，是肌组织衰竭的标志物）、上呼吸道感染、疲乏、头痛、腹痛和咳嗽等。在Tyzeka同一类型的药物中，一些案例出现了体内乳酸积聚过多（乳酸中毒）、严重肿胀、肝脏内脂肪堆积等，有些甚至是致命的。

Tyzeka由瑞士诺华制药有限公司生产（Novartis Pharma Stein AG, Stein, Switzerland），并由马萨诸塞州剑桥市的Idenix制药公司销售（Idenix Pharmaceuticals Inc., Cambridge, Mass.）。

　　　　　　　　　　　　New medication for HB

　　Tyzeka (telbivudine) has been approved for the treatment of adults with chronic hepatitis B, a serious viral infection that attacks the liver and can cause lifelong infection, scarring of the liver (cirrhosis), and eventually liver cancer, liver failure, and death. Tyzeka is a new molecular entity, meaning an active substance that has never before been approved for marketing in any form in the United States.

　　Tyzeka, approved in October 2006, was studied in a yearlong international clinical trial in 1,367 people with chronic hepatitis B. Three-quarters of the trial participants were male, and all participants were 16 years of age or older.

　　The trial produced evidence of antiviral effectiveness, including the suppression of hepatitis B virus (HBV) and improvement in liver inflammation comparable to Epivir-HBV (lamivudine), one of five other medications approved to treat people with chronic hepatitis B.

　　HBV is spread when blood from an infected person enters the body of a person who is not infected, sometimes by sexual contact or by blood contamination. Tyzeka is not a cure for hepatitis B, and long-term treatment benefits are unknown.

　　Most of the side effects of Tyzeka reported in clinical studies were mild to moderate. The most common were elevated creatinine phosphokinase (CPK), an enzyme present in muscle tissue and a marker for the breakdown of muscle tissue, upper respiratory tract infection, fatigue, headache, abdominal pain, and cough. Among drugs in the same class as Tyzeka, some cases have been reported of too much acid in the body due to buildup of lactic acid (lactic acidosis) and to severe enlargement and accumulation of fat in the liver, including fatal cases.

Tyzeka is manufactured by Novartis Pharma Stein AG, Stein, Switzerland, and marketed and distributed by Idenix Pharmaceuticals Inc., Cambridge, Mass.