• Open Access

Counterfeit phosphodiesterase type 5 inhibitors pose significant safety risks


  • Disclosures Graham Jackson is a consultant for Lilly and Pfizer, and a meeting participant for Lilly, Pfizer, and Bayer.
    Stefan Arver has served as a consultant to Pfizer, Eli Lilly, Bayer, and has lectured in meetings sponsored by these corporations. He has received research grants from Bayer.
    Ian Banks is president of the European Men’s Health Forum; a consultant/advisor and meeting participant/lecturer for Pfizer, Jansen Cilage, GlaxoSmithKline and Celgene. He is a visiting professor on European Men’s Health at Leeds Metropolitan University in England, a member of the British Medical Association Council and the president of Men’s Health Forum England & Wales.
    Vera Stecher is employed with Pfizer Inc.

  • Unpublished research (including prescription and survey data and active pharmaceutical ingredient analysis) was sponsored by Pfizer Inc. Editorial support was provided by Tiffany Brake, PhD, and Janet Matsuura, PhD, at Complete Healthcare Communications, Inc., and was funded by Pfizer Inc.

    Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

Graham Jackson, MD, London Bridge Hospital, 27 Tooley St., Suite 301 Emblem House, London SE1 2PR, UK
Tel.: + 44 (207) 407 5887
Fax: + 44 (207) 357 7408
Email: gjcardiol@talk21.com


Counterfeit drugs are inherently dangerous and a growing problem; counterfeiters are becoming increasingly sophisticated. Growth of the counterfeit medication market is attributable in part to phosphodiesterase type 5 inhibitor (PDE5i) medications for erectile dysfunction (ED). Millions of counterfeit PDE5is are seized yearly and account for the bulk of all counterfeit pharmaceutical product seizures. It has been estimated that up to 2.5 million men in Europe are exposed to illicit sildenafil, suggesting that there may be as many illegal as legal users of sildenafil. Analysis of the contents of counterfeit PDE5is shows inconsistent doses of active pharmaceutical ingredients (from 0% to > 200% of labelled dose), contaminants (including talcum powder, commercial paint and printer ink) and alternative ingredients that are potentially hazardous. In one analysis, only 10.1% of samples were within 10% of the labelled tablet strength. Estimates place the proportion of counterfeit medications sold over the Internet from 44% to 90%. Of men who purchase prescription-only medication for ED without a prescription, 67% do so using the Internet. Counterfeit PDE5is pose direct and indirect risks to health, including circumvention of the healthcare system. More than 30% of men reported no healthcare interaction when purchasing ED medications. Because > 65% actually had ED, these men missed an opportunity for evaluation of comorbidities (e.g. diabetes and hypertension). Globally, increased obstacles for counterfeiters are necessary to combat pharmaceutical counterfeiting, including fines and penalties. The worldwide nature of the counterfeit problem requires proper coordination between countries to ensure adequate enforcement. Locally, physicians who treat ED need to inform patients of the dangers of ordering PDE5is via the Internet.