两性健康

Viagra Pfizer: From Accidental Discovery to Globally Trusted ED Treatment

Posted on by 威而钢（伟哥）

Viagra（商品名万艾可）由美国辉瑞制药研发，主要成分为西地那非，是首个口服PDE5抑制剂，用于治疗男性勃起功能障碍。其诞生充满戏剧性：最初作为心绞痛药物研发，却在临床试验中发现对改善勃起功能有显著效果，从而开创了ED治疗的新时代。

Click to buy

该药为蓝色薄膜衣片，规格包括25mg、50mg和100mg。需处方使用，建议在医生指导下按需服用。2022年数据显示，Viagra在全球ED治疗市场中仍占据领先地位，年处方量超800万份。

Viagra (brand name: 万艾可), developed by Pfizer, contains Sildenafil​ as its active ingredient. It was the first oral PDE5 inhibitor approved for treating male erectile dysfunction. Its discovery was serendipitous: initially investigated for angina, clinical trials revealed its significant effects on improving erectile function, revolutionizing ED treatment。

The medication is a blue film-coated tablet, available in 25mg, 50mg, and 100mg strengths. It is a prescription drug intended for use under medical guidance. As of 2022, Viagra maintained a leading position in the global ED treatment market, with over 8 million prescriptions annually。

二、作用机制：如何重启自然勃起功能？ / Mechanism of Action: How Does It Restore Natural Erection?​

Viagra通过高选择性抑制PDE5酶发挥作用。在性刺激下，阴茎血管释放一氧化氮，激活鸟苷酸环化酶，使cGMP水平升高，促使阴茎海绵体平滑肌松弛，血流增加而引起勃起。PDE5酶会分解cGMP，而西地那非可有效抑制PDE5，从而增强和维持勃起硬度。

值得注意的是，Viagra并非催情剂，需性刺激才能起效。其药效可持续4-6小时，推荐在性活动前30-60分钟服用。

Viagra works by selectively inhibiting the PDE5 enzyme. Upon sexual stimulation, nitric oxide released in the penile blood vessels activates guanylate cyclase, increasing cGMP levels. This leads to relaxation of the smooth muscles in the corpus cavernosum, allowing increased blood flow and resulting in an erection. Sildenafil enhances this process by inhibiting PDE5, which normally breaks down cGMP, thereby improving erection hardness and sustainability。

It is crucial to note that Viagra is not an aphrodisiac​ and requires sexual stimulation to work. Its effects can last 4-6 hours, and it is typically taken 30-60 minutes before sexual activity。

三、用法与剂量：个性化方案提升治疗效果 / Usage and Dosage: Personalized Regimen for Optimal Efficacy​

  1. 标准剂量：
    • 推荐起始剂量为50mg，性活动前1小时服用。
    • 可根据疗效和耐受性调整至100mg或降至25mg。
  2. 特殊人群调整：
    • 65岁以上、肝肾功能不全者从25mg开始。
    • 服用强效CYP3A4抑制剂者剂量不超过25mg/48小时。
  3. 服用提示：
    • 空腹或餐后服用均可，高脂餐可能延迟吸收。
    • 24小时内不超过1次，避免与硝酸酯类药物同用。
  4. Standard Dosage:
    • The recommended starting dose is 50mg, taken about 1 hour before sexual activity。
    • The dose can be increased to 100mg or decreased to 25mg based on efficacy and tolerance。
  5. Adjustments for Specific Populations:
    • For patients over 65 or with hepatic/renal impairment, start with 25mg。
    • When co-administered with strong CYP3A4 inhibitors, dose should not exceed 25mg per 48 hours。
  6. Administration Tips:
    • Can be taken with or without food, but high-fat meals may delay absorption。
    • Do not exceed one dose within 24 hours. Avoid concurrent use with nitrates。

四、优势与特点：为何仍是经典选择？ / Advantages: Why It Remains a Classic Choice?​

优势维度 / Aspect 具体特点 / Characteristics
研发背景​ 原研药，辉瑞拥有完整临床数据与质量控制体系。
起效速度​ 30-60分钟起效，4-6小时持续时长，适合多数场景。
剂量灵活性​ 3种规格可选，便于个体化调整。
长期安全性​ 超20年临床应用，安全性得到充分验证。

五、注意事项与常见疑问 / Precautions and Frequently Asked Questions​

Q1: Viagra是否适合所有ED患者？​

A1: 需医生评估。严重心血管疾病、服用硝酸酯类药物者禁用。

Q2: 副作用如何管理？​

A2: 常见副作用如头痛、面部潮红通常轻微，多喝水可缓解。严重副作用罕见。

Q3: 能否每日服用？​

A3: 不推荐。应按需使用，最大频率为每日1次。

Q1: Is Viagra suitable for all ED patients?​

A1: A doctor’s assessment is necessary. It is contraindicated in patients with severe cardiovascular diseases or those taking nitrates。

Q2: How to manage side effects?​

A2: Common side effects like headache and flushing are usually mild; drinking water may help. Serious side effects are rare。

Q3: Can it be taken daily?​

A3: Not recommended. It is for on-demand use, with a maximum frequency of once daily。