PDE-5 Inhibitors: A Prime Target for Counterfeiters
Sexual health medications such as the phosphodiesterase-5 (PDE-5) inhibitors and other so-called "embarrassment drugs" such as finasteride (Propecia) are prime candidates for counterfeiting. One feature that makes them attractive to counterfeiters is their relatively high cost, which promises a high profit margin to those who trade illicitly in them. Also, because these drugs are for treating conditions associated with a certain amount of shame and embarrassment, patients are willing to pay out of pocket in order to not have to discuss the issue with their doctors.[10] The best known of the "embarrassment drugs" is sildenafil (Viagra), which may be the most commonly counterfeited prescription drug in the world. Since its introduction in the late 1990s, sales of this drug, which retails for about $10 a pill, have grown exponentially. In 2003, about 15 million prescriptions were written.[9]
Given its popularity and expense, there are obvious financial gains to be realized though the sale of counterfeit PDE-5 inhibitors such as sildenafil. In 2004 alone, law officers seized 10.1 million counterfeit sildenafil tablets, which was 7 times the number of all other counterfeited Pfizer products combined. A recent report by Cyveillance, Inc. estimated that upwards of 488,000 tablets of unapproved generic forms, 90,000 tablets of alternative forms, and 36,000 tablets of herbal forms of sildenafil are sold each month. Many of these are purchased without a prescription via online vendors who sell sildenafil and "herbal" medications containing sildenafil and other PDE-5 inhibitors.
The Role of the Internet and Online Pharmacies
Probably most of the counterfeit PDE-5 inhibitors in the United States enter the market via illicit distribution by fraudulent Web sites. It is estimated that between 4500 and 15,000 Web sites offer online ordering of PDE-5 inhibitors and other substances that are claimed to treat erectile dysfunction. These sites receive approximately 12.9 million visitors per month and sell an estimated 2.3 million tablets per month, many without a prescription. Although the number of online pharmacies operating today is unknown, it is expected that Internet pharmaceutical sales will grow to an estimated $13.2 billion by the end of 2007, or around 4% of total pharmaceutical sales in the United States.[11]
The good side of Internet pharmacies is that they allow consumers to fill prescriptions at their convenience, regardless of store hours. The bad side is that they can allow patients to bypass the traditional doctor-patient relationship and its safeguards, creating a dangerous opportunity for drug abuse and/or unchecked medication interactions and side effects. The decentralized nature of the Internet also provides an ideal environment for rogue online pharmacies to sell and distribute counterfeit or otherwise
fraudulent medications.[11]
While there are many online pharmacies that offer a wide variety of legitimate services and follow good dispensing practices determined by the National Association of Boards of Pharmacy or similar regulatory bodies, there are many who do not. Legitimate pharmacies dispense medications only with a valid prescription from a licensed healthcare provider that is verified for its authenticity. By contrast, rogue pharmacies waive this important patient safeguard and either do not require a prescription at all or determine the need for medications on the basis of questionnaires or "cyber-doctors" without a consultation or physical exam from a licensed physician or physician assistant with prescribing privileges.
Indeed, studies investigating the availability of medications on the Internet estimate that about 20% of online pharmacies do not require prescriptions at all. In one study, a researcher posing as a 45-year-old man with a significant history of heart disease currently taking nitrates approached a number of online pharmacies requesting sildenafil.[11] Despite his having stated clear contraindications for sildenafil, 1 of 5 Internet pharmacies approached actually provided the medication. A similar study conducted by Eysenbach[12] involving a fictitious 69-year-old female with a chief complaint of "no orgasm" and a medical history of coronary artery disease and hypertension who was taking erythromycin yielded similar results. In this study, 30% of online pharmacies issued prescriptions despite lack of approved indication for sildenafil for female anorgasmia and clear contraindications for its use. Additionally, one pharmacy offered to ship sildenafil with cimetidine because, as it stated, the drug induces "56% increase in plasma sildenafil concentrations when coadministered with Viagra."[12] This is a potentially dangerous combination and a well-known contraindication.
The problems of Internet-based distribution of prescription drugs go beyond the sometimes questionable medical judgment exhibited by online pharmacies. Another worrisome problem is the difficulty of policing for adequate quality control. There is very little that may be done to safeguard patients who order drugs online against counterfeit, unsafe, or illegal medications. A recent study using near-infrared microscopy, conducted by the Royal Pharmaceutical Society of Great Britain at the University of London School of Pharmacy, found that "around half the Viagra samples purchased on the Internet were counterfeit."[13]
Nor are rogue Internet pharmacies necessarily cheaper than licensed pharmacies. The actual costs of drugs purchased on the Internet, regardless of their authenticity, may be more than the costs of the real drugs at traditional pharmacies. In fact, Eysenbach[12] estimated that the Internet costs were roughly double the costs of sildenafil purchased at regular pharmacies. In many cases, the supposed savings are eroded by hidden costs, shipping, and fees for online cyberdoctors.
Illegal Generic Brands and Reformulations
Illegal generics are non-FDA-approved versions of branded pharmaceuticals, which may contain varying and inconsistent amounts of active ingredients. These "generics" are often sold at significant price discount to branded products. Patients who are used to buying legitimate generic versions of over-the-counter drugs may be unaware that there is no FDA-approved "generic" version of the PDE-5 inhibitors. Plentiful email advertisements and pop-ups might certainly give the impression that sildenafil exists in generic form.
Analysis of substances sold as generic sildenafil reveals that they are frequently less than pure in their ingredients. Vredenbregt and colleagues{14] evaluated 103 samples purchased online using a new screening technique involving near-infrared spectroscopy. The samples were found to contain varying amounts of sildenafil as well as other active ingredients such as clomiphene citrate, yohimbine, quinine, amphetamine, and dipyrone.[14]
Unapproved reformulations of existing agents are another type of counterfeit medication for erectile dysfunction. These reformulations are advertised as offering new modalities of delivery or administration, such as fast-dissolving lozenges or gel tabs. Again, the concentration and source of active ingredient are often unknown and rarely printed on the packaging. The safety of these reformulations is questionable at best.
Medscape Urology © 2007 Medscape
Cite this: The Illicit Sale of Medications for the Treatment of Erectile Dysfunction - Medscape - Dec 11, 2007.
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