FDA批准新型避孕药

ST LOUIS (MD Consult) - On May 6, 2010, the US Food and Drug Administration (FDA) and Bayer HealthCare Pharmaceuticals announced the approval of Natazia (estradiol valerate and estradiol valerate/dienogest) tablets for the prevention of pregnancy. According to Anita Nelson, MD, professor of obstetrics and gynecology at the Harbor-UCLA Medical Center in Torrance, Calif, "Every woman's body reacts differently to hormones, so it is important that they have a choice in birth control options. Natazia may be a good option for women to consider when making a decision with their health care provider about which birth control option is right for them."

An FDA press release states that Natazia is the first four-phasic oral contraceptive approved for marketing in the United States. Four-phasic refers to the doses of progestin and estrogen varying at 4 times throughout each 28-day treatment cycle. Another difference between Natazia and previously marketed combination oral contraceptives (COCs) is that it contains estradiol valerate instead of ethinyl estradiol as the estrogen component.

The safety and efficacy of Natazia as an oral contraceptive agent was evaluated in 2 multicenter phase 3 clinical trials in North America and Europe involving 1,867 women and almost 30,000 28-day treatment cycles. Natazia was found to be effective as a hormonal contraceptive in both studies.

The most common adverse effects observed with Natazia include irregular bleeding, breast tenderness, headaches, nausea, vomiting, increased weight, and acne.

Natazia should not be used in women with a high risk of arterial or venous thrombotic diseases, undiagnosed abnormal genital bleeding, breast cancer or other estrogen- or progestin-sensitive cancer, liver tumors (benign or malignant), or liver disease. The use of Natazia is associated with increased risks of several serious conditions including venous and arterial thrombotic and thromboembolic events (including myocardial infarction, thromboembolism, and stroke), hepatic neoplasia, gallbladder disease, hypertension, ruptured ovarian cysts, and uterine leiomyoma. The excess risk of thromboembolic events is highest during the first year of COC use.

Women using COCs, including Natazia, should be strongly advised not to smoke. Smoking increases the risk of serious cardiovascular untoward effects from COC use. The risk increases with age and the number of cigarettes smoked.

Natazia has not been evaluated in women with a body mass index >30 kg/m².

圣路易斯(MD Consult)——2010年5月6日，美国食品药品管理局(FDA)和拜耳制药公司(Bayer HealthCare Pharmaceuticals)宣布，避孕药Natazia (戊酸雌二醇和戊酸雌二醇/地诺孕素)片剂正式获批。美国加州托兰斯加州大学洛杉矶分校Harbor医学中心的妇产科教授Anita Nelson博士说：“每位女性对激素的机体反应都有所不同，因此有必要提供多种避孕选择。她们在与医务人员共同决定采用哪种避孕措施对其最为恰当时，Natazia应该是值得考虑的不错选择之一。”

FDA在新闻发布会上称，Natazia是首个在美国获准上市的四相口服避孕 (http://www.chemdrug.com/brand/zs.asp?bigclassname=%E5%8C%BB%E7%96%97%E5%99%A8%E6%A2%B0&smallclassname=%E9%81%BF%E5%AD%95%E5%99%A8%E6%A2%B0)药。四相是指在每个为期28天的治疗周期内4次口服孕激素和雌激素的剂量各不相同。Natazia与之前上市的复方口服避孕药(COC)相比还有一点区别，即所含的雌激素成分为戊酸雌二醇，而非乙炔雌二醇。

在北美和欧洲开展的两项多中心3期临床试验 (http://www.chemdrug.com/tradeinfo/trade/11.html)对Natazia作为口服避孕药的安全性和有效性进行了评估。这两项试验共纳入1,867例女性，共观察了近30,000个为期28天的治疗周期。这两项试验均证实，Natazia作为一种激素类避孕药是有效的。

已观察到的Natazia的最常见不良反应包括：不规则出血、乳房触痛、头痛、恶心、呕吐、体重增加和痤疮。

对于动脉或静脉血栓形成性疾病、诊断不明的生殖器异常出血、乳腺癌或其他雌激素或孕激素敏感性癌症、肝脏肿瘤(良性或恶性)或肝脏疾病高危人群，应避免使用Natazia。使用Natazia可能导致出现多种严重疾病的风险增加，包括静脉和动脉血栓形成性和血栓栓塞性事件(包括心肌梗死、血栓栓塞和卒中)、肝脏肿瘤、胆囊疾病、高血压、卵巢囊肿破裂和子宫平滑肌瘤。在使用COC的第1年里，血栓栓塞性事件的风险增幅最高。

对于使用包括Natazia在内的COC产品的妇女，强烈建议其不要吸烟。吸烟会进一步增加因使用COC而引起的严重心血管不良反应的风险。年龄越大，吸烟量越大，风险就越高。

尚未在体重指数>30 kg/m²的女性中对Natazia开展过评价。