Each year, millions of men rely on pharmaceuticals like Viagra and Cialis for their erectile dysfunction (ED), but they may not be the only ones facing dysfunctionalities.  As the patents on these lucrative lifestyle drugs come to an end, price tags and bottom lines are expected to plummet.
PDE5 Inhibitors
Viagra made by Pfizer and Cialis by Eli Lilly are phosphodiesterase type 5 (PDE5) inhibitors which break down cyclic guanosine monophosphate (cGMP).  In a gross simplification, after sexual stimulation, an erection occurs through the release of nitric oxide (NO) which causes dilation of blood vessels due to an accumulation of (cGMP).  Dysfunction occurs when cGMP conflicts with the NO vasodilatory effects. When the PDE5 inhibitor is introduced, the cGMP is broken down.  So, less cGMP means more blood flow et voilà, an erection.
There are differences between these drugs, though.  For example, Viagra is made with sildenafil and has a wait time of 30-60 minutes lasting for up to 4 hours. Cialis’ main ingredient is tadalafil and can either be taken daily (meaning it is always active in the body) or 30 minutes to 12 hours before activity to last up to 36 hours. This longer lasting formula is one of the benefits over the “little blue pill” which has proved to be more appealing to most men.  Further, sildenafil and tadalafil have different chemical and molecular structures.
Viagra and Cialis Patent Protection
The success of these drugs has been guaranteed in large part by securing IP rights across the globe.  Viagra was approved by the FDA in the United States in 1998 and Cialis in 2003, but their patent journeys occurred earlier.
The first patent for Viagra was filed in May 1994and was issued in 2002, but Viagra did not begin as an ED pill.   The compound was originally developed and patented as a drug called Revatio to treat high blood pressure (hypertension) and chest pain due to heart disease (angina pectoris), but clinical trials showed that it was more effective at inducing erections than anything else.
The drug was then renamed and patented as Viagra. Viagra was a pre-GATT application because it was filed before June 8, 1995, so it got the benefit of choosing its expiration date: either 17 years from the issue date of 2002, that is to say October 2019 or 20 years from filing, with rights lapsing in May 2014.  Naturally, Pfizer selected the later October 2019 date.  Further, through the FDA, the expiration was extended another 6 months to April 2020 due to a special pediatric exclusivity testing Revatio’s effect on pulmonary arterial hypertension.
With the expiration of Viagra three years away, you would think that the market for generics would be on hold until then.  However, an Israeli manufacturer named Teva Pharmaceutical Industries Ltd. will be allowed to sell a generic version of Viagra beginning December 11, 2017. Since several patents outside the US have already expired, an undisclosed deal was arranged after Pfizer sued Teva and Teva was authorized to launch a generic version.  The settlement stipulates that the generic manufacturer will have to pay royalties to Pfizer through the April 2020 patent expiration date. Teva’s inventory has already been approved by the FDA for three different strengths of sildenafil citrate and the company has been selling a generic in the European Union since 2013.
Cialis came to market after an over five-year monopoly of Viagra as the only prescription drug on the market to treat ED.  In its first year, Viagra sales revenue exceeded $1 billion, but its profit margins declined with the introduction and FDA approval of Levitra (another ED antidote) in August 2003 and Cialis in November 2003.  Cialis was discovered in August 1991 by a company named Icos and was later purchased by Eli Lilly. Patent protection expires at the end of this year, so the company will still be able to register a profit during almost the entirety of 2017 before getting crushed by generics.
Like Viagra, Cialis is also used to treat pulmonary arterial hypertension and was approved as such in the US in May 2009.  Another similarity is that Eli Lilly struck a licensing deal with the French company Sanofi to maximize any profits it possibly can before the patent expires.  In 2014, an announcement of this licensing agreement was made where Sanofi will sell an over-the-counter version of Cialis in the U.S., Europe, Canada and Australia when specific patents expire.  Lilly will make its money through the licensing fees.
Another way Pfizer and Eli Lilly have tried to recoup lost sales is by making the drugs over-the-counter medications and selling them directly through their websites.  By doing this, the companies goals are to capture sales from those who are too embarrassed by the social stigma of impotence and who do not want to discuss their condition with a doctor.

Lifestyle vs. Lifesaving Drugs
Viagra and Cialis are lifestyle drugs.  This label means that they treat “lifestyle illnesses” arising from lifestyle choices like smoking, weight gain, and alcoholism or ailments like baldness, dry skin, wrinkles, ED and hot flashes.  These medicines may improve a patient’s life, function or appearance and may not be medically necessary or therapeutic. One way to look at them is that they enhance a patient’s life instead of extending it. These are unlike life-saving pharmaceuticals used to cure or manage illness and generally improve health, like cancer or HIV medications.  The good news for ED drugs is that they are reasonably secure in their patents under Trade-Related Aspects of Intellectual Property Rights Agreement (TRIPS).  It is less likely that countries facing major pandemics like HIV/AIDS, malaria and Zika will be too concerned with needing lower priced drugs for ED, weight loss or crow’s feet, unless the drugs have other, more relevant, implications.
The lifestyle drug market is extremely lucrative. These medications can be used by all age groups worldwide and increased individual awareness of health and beauty has created a demand for physical fitness and improved performance of all our body parts.  People are living longer, have higher disposable income, and the demand only grows more when a drug touts the high quality and safety of their formulations after it passes the stringent requirements for FDA approval. Additionally, a greater number of people are turning to pharmaceuticals to “treat” ordinary ailments, mild symptoms and personal problems, thinking that a pill is the answer to all their problems. Also good for the Pfizers and Eli Lillys of the world is that since the pharmaceuticals are not curing a disease or problem, but rather treating an issue (such as ED, cholesterol or high blood pressure) the patient takes daily doses and usually over many years.  This is unlike an antibiotic that is taking for a finite duration and once the taker is cured they no longer need the drugs, effecting that medicines bottom line.
Further, since lifestyle drugs have a better shot at being successful economically because they can be sold to more people, drug companies are more likely to continue to create and invest in those rather than medicines for, say, malaria, where the patients are fewer and too poor to pay enough to offset the sky-high R&D costs.
Conclusion
Lifestyle drugs like Viagra and Cialis have been an extraordinary success for drug companies for many years. It will be difficult to replace the revenue of these blockbuster drugs once they go off patent in the United States, but when that happens consumers can expect generics to race into the marketplace and for prices to fall. The real question, however, is whether U.S. patent law and policy will continue to give pharmaceutical companies the incentives necessary to innovate lifesaving medicines, or whether we will continue to see more and more blockbuster lifestyle drugs moving into the future.