FDA批准阿伐那非治疗男性勃起功能障碍
2012年4月27日，美国食品与药物管理局（FDA）批准新药阿伐那非（Stendra）治疗勃起功能障碍（ED），ED患者可在进行性行为之前30分钟根据需要服用该药。FDA提示，医生应处方使患者获益的最小剂量阿伐那非。
阿伐那非属于5型磷酸二酯酶抑制剂（PDE5-I），它可增加阴茎的血流量。与其他PDE5-I相同，该药不能用于同时服用硝酸盐类治疗胸痛的男性患者，因为其联合使用会导致血压的急剧降低。
PDE5-I很少引起色视觉的改变，有报道在一些罕见的情况下，服用PDE5-I的男性突然出现单眼或双眼的视力丧失，还有可能突然发生听力丧失或下降。一旦出现上述情况，患者应停止服用PDE5-I，包括阿伐那非，并立即呼叫医生。
在临床试验中，超过2%的患者记录的最常见不良反应包括头痛，面部和身体其他部分的潮红，鼻充血，常见的感冒样症状（鼻咽炎）和后背痛。罕见有服用阿伐那非或其他PDE5-I的患者出现阴茎异常勃起可能持续4小时或更长时间。如果这一情况出现，患者应及时就医。
3项双盲、安慰剂对照临床试验确定了阿伐那非的安全性和有效性。试验纳入的1267例患者被随机分为阿伐那非组和安慰剂组，这些患者都在进行性行为之前的30分钟服用阿伐那非或安慰剂，阿伐那非组分别接受阿伐那非50mg、100 mg 或200 mg治疗12周。
研究的开始和此后的每4周对患者进行调查问卷，以评估其勃起功能等性交情况。结果显示，服用3个不同剂量的阿伐那非患者所有3项评估终点均有显著改善。
为进一步评估阿伐那非的安全性，两项亚组研究予患者起始应用阿伐那非100 mg治疗，但可能根据患者对治疗的反应情况，增量到200 mg或减量至50mg。结果显示，随着时间变化，亚组患者记录的不良反应并没有恶化。
详情说明书
http://www.stendra.com/assets/pdf/STENDRA-avanafil-tablets-Patient-Information.pdf
IMPORTANT SAFETY INFORMATIONSTENDRA(avanafil) is indicated for the treatment of erectile dysfunction (ED).
The use of STENDRA and organic nitrates in any form, at any time, is contraindicated.
Before treating ED, physicians should consider the impact of resuming sexual activity and the mild and transient vasodilatory effects of STENDRA
on blood pressure. Physicians should carefully consider whether patients with underlying cardiovascular disease or other more unusual conditions
could be adversely affected by vasodilatory effects, especially in combination with sexual activity.
For patients taking concomitant strong CYP3A4 inhibitors (including anti-fungals ketoconazole, itraconazole; protease inhibitors for HIV ritonavir, atazanavir, indinavir, nelfinavir,saquinavir; antibiotics clarithromycin and telithromycin; and the antidepressant nefazodone,), use
of STENDRA is not recommended.
As there have been infrequent reports of prolonged erections lasting more than 4 hours or priapism with all ED treatments in this drug class,
patients should be advised to seek immediate medical attention should these occur. Erections lasting longer than 6 hours can result in penile
tissue damage and long-term loss of potency.
Non-arteritic anterior ischemic optic neuropathy (NAION) has been reported rarely post-marketing in temporal association with the use of PDE5 inhibitors. It is not possible to determine if these events are related to PDE5 inhibitors or to other factors. Physicians should advise patients to stop use of PDE5 inhibitors, including STENDRA, and seek medical attention in the event of sudden loss of vision.
Sudden decrease or loss of hearing has been reported in temporal association with the intake of PDE5 inhibitors. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors. Physicians should advise patients to stop taking PDE5 inhibitors, including STENDRA, and seek prompt medical attention in the event of sudden decrease or loss of hearing.
Physicians should advise patients of the potential for PDE5 inhibitors, including STENDRA, to augment the blood pressure lowering effect of alpha
blockers and anti-hypertensive medications. In some patients concomitant administration of a PDE5 inhibitor and alpha blocker may lead to symptomatic hypotension. Patients should be stable on alpha-blocker therapy prior to taking STENDRA.
Patients should b