Mati pucuk
Viagra: A World-Changing Accidental Discovery
Viagra（西地那非，Sildenafil）的故事是医药史上最著名的“意外收获”之一。这款由辉瑞（Pfizer）公司研发的蓝色小药丸，最初的目标是治疗心绞痛（一种由流向心脏的血液减少引起的胸部疼痛）。
The story of Viagra (Sildenafil) is one of the most famous cases of “serendipity” in medical history. This little blue pill, developed by Pfizer, was originally intended to treat angina, a type of chest pain caused by reduced blood flow to the heart.
Click to buy在20世纪90年代初的临床试验中，研究人员发现这种化合物对心绞痛的效果并不理想。然而，参与试验的男性志愿者报告了一个意想不到的“副作用”：他们经历了勃起功能的改善。一些参与者甚至拒绝在试验结束后归还未使用的药片。这个偶然的观察让研究团队意识到，他们可能发现了一种治疗勃起功能障碍（ED）的革命性方法。
During clinical trials in the early 1990s, researchers found the compound was not very effective against angina. However, male volunteers reported an unexpected “side effect”: they experienced improved erectile function. Some participants even refused to return their unused pills at the trial’s conclusion. This chance observation led the research team to realize they might have discovered a revolutionary treatment for Erectile Dysfunction (ED).
从实验室到现象级药物：Viagra 的商业成功
From Lab to Blockbuster: The Commercial Success of Viagra
辉瑞公司迅速调整了研发方向，并于1998年获得美国FDA批准，将Viagra作为治疗勃起功能障碍的药物推向市场。它是首个治疗此症的口服药物，相较于当时常见的阴茎注射等非口服疗法，其便利性引发了巨大轰动。
Pfizer quickly pivoted its R&D focus and received FDA approval in 1998 to market Viagra for ED. As the first oral medication for this condition, its convenience compared to contemporary non-oral treatments like penile injections caused a sensation.
Viagra迅速成为一种文化现象。上市后第一年，其全球销售额即达到约4亿美元；在其商业巅峰时期，年均全球销售额估计高达18亿美元。它不仅是商业上的巨大成功，也显著促进了公众对男性性健康的公开讨论。
Viagra quickly became a cultural phenomenon. In its first year, it generated approximately 1.8 billion[^^1]. It was not only a massive commercial success but also significantly promoted public dialogue about men’s sexual health.
作用机理：蓝色小药丸如何工作？
Mechanism of Action: How Does the Little Blue Pill Work?
Viagra的有效成分西地那非通过抑制5型磷酸二酯酶（PDE5）发挥作用。在性刺激下，阴茎血管会释放一氧化氮（NO），进而促进环磷酸鸟苷（cGMP）的生成，使血管平滑肌松弛，增加血流量，引发勃起。而PDE5会分解cGMP。西地那非通过抑制PDE5，有效维持cGMP的水平，从而帮助男性在性刺激时获得并维持勃起。
Viagra’s active ingredient, Sildenafil, works by inhibiting phosphodiesterase type 5 (PDE5). During sexual stimulation, the blood vessels in the penis release nitric oxide (NO), which promotes the production of cyclic guanosine monophosphate (cGMP), relaxing smooth muscles in the blood vessels and increasing blood flow to facilitate an erection. PDE5 breaks down cGMP. By inhibiting PDE5, Sildenafil helps maintain cGMP levels, thereby assisting men in achieving and maintaining an erection with sexual stimulation.
深远影响与未来
Lasting Impact and Future
尽管后来发现了西地那非在治疗肺动脉高压等心脏疾病方面的用途，且专利到期后面临仿制药的竞争，但Viagra的遗产是深远的。它源于一次意外的观察，最终改善了数百万男性的生活质量，并勇敢地打破了围绕性健康话题的沉默。
Although Sildenafil was later found to be useful for heart conditions like pulmonary arterial hypertension, and faced competition from generics after its patent expired, Viagra’s legacy is profound. It originated from an accidental observation and ultimately improved the quality of life for millions of men, while courageously breaking the silence surrounding sexual health discussions.