忘记用户 ID? or 忘记密码?

Not a Member?


Menu 返回 Poster-Presentations-Details

M-01: Impact on the Cost and Safety of Generic Sildenafil Citrate in the USA

Poster Presenter

      Alexander Agyei Marfo

      • Student
      • Touro
        United States


To evaluate the impact of the recent approval of generic Sildenafil on the total cost and safety of Public Health in the United States, and its effects on counterfeits.



Review of literature including a search of PubMed and Google Scholar using the keywords "counterfeits," "cost," "safety" and "Sildenafil." Was conducted. The US FDA and the WHO websites were also reviewed for additional information. Eight articles were included in the study.


Sildenafil Citrate, an erectile dysfunction (ED) drug made over 1.5 billion in revenues by 2016. The patent for sildenafil at doses for ED expired in 2012 outside the U.S while in the U.S it is set to expire in April 2020. This is expected to give rise to many generic versions. On September 3, 2016, Teva Pharmaceuticals and Greenstone were both approved by the FDA to produce and sell Sildenafil in the U.S. Pfizer currently sells brand sildenafil at $61.54 while Greenstone sells the generic version between $30 and $35 a pill. Pfizer surveilled online search results for the word "Brand Sildenafil" for two best internet search sites in March 2011. Twenty-two distinct sites claiming to sell brand Sildenafil made by Pfizer were tracked. Tablets from these websites were assayed. None of the websites needed a prescription for orders, 90% offered illegal "generic sildenafil." Price of tablet ranged from $3.28-$33. Purchases were shipped from the United States (N = 6), Hong Kong (N = 11) and the United Kingdom (N = 2) as well as Canada, China, and India (N = 1 each). Of the 22 sample tablets examined,17 (77%) were counterfeit, four (18%) were authentic, and one (5%) was an illegal generic. None of the internet pharmacies claiming to be Canadian shipped medication from a Canadian address. Counterfeit tablets were analyzed for sildenafil citrate, the active pharmaceutical ingredient of brand Sildenafil, and contents varied between 30% and 50% of the label claim. A study from the Philadelphia area compared (N=37) sites that offered online sildenafil and found the median per-tablet price was 22% higher than brand sildenafil from pharmacies in the area. This price did not include online physician consultation fee which was 17% higher than the price paid by Medicaid for a primary care physician visit. It could be inferred that the reason consumers prefer internet purchases is not the price competitiveness but rather privacy and circumvention of the requirement of prescript


In conclusion, although generic sildenafil will make the ED drug market more competitive by providing consumers a lower-cost option, it may not solve the problem of privacy and circumvention of the requirement of prescriptions. Counterfeited sildenafil may take advantage of this vast market, which would raise concerns about safety among consumers.