The History
Viagra is the trade name for sildenafil citrate, which was initially developed as a treatment for erectile dysfunction. After its approval and rapid dissemination as a sexual performance enhancer, controversy followed.
Sildenafil citrate is a phosphodiesterase type 5 (PDE5) inhibitor. This mechanism of action selectively relaxes the penile muscles, allowing blood to flow into the penis and sustaining an erection for more intimate moments. [Blog article]:
The Science
The PDE5 inhibitors, which include sildenafil citrate, are a class of medications that work through a similar mechanism. Studies suggest that the drugs can benefit patients with erectile dysfunction (ED), including those who may not be able to take nitrates or other medications due to a history of hemorrhage or heart disease.
One double-blind, placebo-controlled trial of sildenafil citrate for the treatment of ED found that out of the 131 men who completed the study, 63% of those who took the drug reported improvements in erectile function compared to 27% of those who took a placebo. [Blog article]:
The Regulation
In the US, sildenafil citrate is currently classified as a prescription drug (Rx). In 2012, Viagra was the top-selling branded drug in the country with an estimated market share of 19.1%, followed by Cialis (14.7%), Levitra (11.9%), and finally, Insignia (7.3%).
However, in a number of countries, including the UK and Australia, Viagra is a nonsubstitutable drug and is, therefore, sold over the counter (OTC). In these countries, it is regulated as a health food supplement (HFS) and is, therefore, freely available to the public without a prescription.
Viagra is generally well-tolerated. The most common adverse effects are headache, upset stomach, and visual disturbances. [Blog article]:
The Economics
In the UK, Viagra is widely available OTC and is usually prescribed as a treatment for ED, with approximately 59,000 prescriptions written per year. According to the UK General Practitioner (GP) survey, the drug was the second most commonly prescribed medication for ED in 2012 (after Levitra), and the most commonly prescribed medication in the country from 2009 to 2011.
In Australia, Viagra is listed in the Pharmaceutical Benefits Scheme (PBS), which covers most medications prescribed or available OTC in the country. It is one of the most commonly prescribed medications for ED in the country, with approximately 17,600 prescriptions written in 2013.
In the US, Viagra is generally prescribed for ED, with an estimated 400 million prescriptions written annually. In 2012, the drug was the eighth most commonly prescribed medication in the country. [Blog article]:
The Law
As with any new medication, legal issues emerged around Viagra as it became more widely prescribed for sexual performance issues. In the US, before it was approved for therapeutic use in 1998, sildenafil citrate was investigated by the FDA for use as a treatment for erectile dysfunction. In 1993, in the landmark decision Buckman v. Plaintiffs, the courts found that sildenafil citrate was a new drug that had not been approved by the FDA as a treatment for ED in accordance with the Federal Food, Drug and Cosmetic Act (FFDCA). The plaintiffs in this case filed an action against the drug company for violating the FFDCA, and the courts eventually ordered the drug company to pay the plaintiffs $114.4 million.
This case established the principle that new medications, including those for sexual performance, must first be approved by the FDA before being marketed in the country.
The Controversy
As with any new medication, the introduction of Viagra to the market sparked controversy. While some hailed it as a life-changing drug for improving erectile function for men with ED, others expressed concern about the off-label use of the medication and its potential for causing serious side effects.
Critics of the drug have pointed out that the initial trials were designed to show only whether or not sildenafil citrate was superior to a placebo and did not address the issue of whether or not the drug actually improved sexual function in men with ED. Further, since the approval of the drug, studies have suggested it may be associated with a variety of adverse effects, including heart attack, stroke, and even death.
The Debate Continues
In September 2012, the FDA approved expanded access for men with ED who were not able to take PDE5 inhibitors due to renal impairment or heart disease. However, the agency did not recommended the drug for use in these patients and instead advised that they take it only under close medical supervision.
In January 2013, at the annual meeting of the American Medical Association, it was announced that Viagra will be available for prescription in a generic form without requiring a doctors’ consultation. Many hailed this decision as a step forward in the battle against ED, while others expressed concern that making the drug more readily available may increase the risk of overprescription and even lead to dangerous off-label use.
This decision has sparked a re-evaluation of the role of Viagra in the treatment of ED. Some suggest that as a result of the generic availability, doctors may consider prescribing the medication earlier in the course of a patient’s disease, which could potentially be harmful. [Blog article]:
The Final Word
Overall, Viagra represents a major step forward in the fight against ED. Most healthcare professionals now agree that the drug can be quite helpful in reversing the effects of aging on a man’s sexual performance. However, since it is a medication that is widely available OTC in the country, it raises significant concerns about whether or not men are aware of the risks associated with its use.
Further, as with any new medication, healthcare providers must remain aware of the latest developments regarding the drug. While the approval of Viagra for therapeutic use seems logical given its demonstrated effectiveness in the treatment of ED, it raises questions about whether or not it was necessary to require that the medication be prescribed by a doctor before being made available for purchase.