Pfizer submitted a New Drug Application (NDA) to the FDA for sildenafil in 1998. The NDA included extensive data from clinical trials demonstrating sildenafil’s efficacy and safety in treating erectile dysfunction. These trials rigorously assessed the drug’s effects on various patient populations and monitored potential side effects.
Phase 1, 2, and 3 Trials
Before NDA submission, Pfizer completed three phases of clinical trials. Phase 1 evaluated the drug’s pharmacokinetics and safety in a small group of healthy volunteers. Phase 2 explored the drug’s efficacy and safety in a larger group of patients with erectile dysfunction. Finally, Phase 3 involved large-scale, multi-center trials that provided conclusive evidence of sildenafil’s effectiveness and safety profile. This robust data package was crucial for FDA review.
FDA Review and Approval
The FDA’s rigorous review process involved a thorough examination of all submitted data, including manufacturing processes and proposed labeling. Scientists evaluated the data for efficacy, safety, and quality. Following a comprehensive review, the FDA approved Viagra (sildenafil) for the treatment of erectile dysfunction in March 1998. This approval was based on the convincing evidence presented by Pfizer demonstrating sildenafil’s beneficial effects and acceptable risk profile.
Post-Market Surveillance
Even after approval, the FDA continues to monitor Viagra’s safety and efficacy through post-market surveillance. This ongoing monitoring allows for the detection of any unexpected adverse events or changes in the drug’s performance. This continuous evaluation ensures the drug remains safe and effective for patients.
