One of the most successful drugs in the history of the pharmaceutical industry is poised to lose its patent this November. That means cheaper generic copycats will soon become available.
One way that drug companies often try to extend profitability when a successful prescription medication goes generic is to take the brand over the counter. Examples include heartburn medicines such as Tagamet, Zantac, Pepcid, Prilosec and Prevacid.
Allergy medicines such as Allegra, Claritin and Zyrtec were all once available only with a prescription. Now they are successful OTC brands.
Exactly what determines whether a medication requires a prescription from a physician? A big part of the answer is safety. Until 1951, there was no distinction between prescription and OTC medicines. Then the Federal Food, Drug, and Cosmetic Act was amended to restrict the sale of medications considered unsafe without medical supervision.
These include drugs that can be habit-forming or toxic, or those whose method of use (read injection) makes them risky for self-administration. They also include a generous loophole that allows the Food and Drug Administration a large amount of wiggle room: drugs that have a potential for harmful effects. The FDA gets to exercise its judgment on which harmful effects are serious enough to keep a medication behind the counter.
The trouble is that all drugs have a potential for harmful effects, but some are more troublesome than others. In recent years, we have learned that popular pain relievers such as ibuprofen (Advil, Motrin IB) pose a risk not only to the digestive tract but also to the cardiovascular system. Studies suggest that this and other nonsteroidal anti-inflammatory drugs (NSAIDs) can raise blood pressure, harm kidneys, trigger irregular heart rhythms and increase the risk of heart attacks and strokes in susceptible individuals (BMJ online, July 4, 2011; American Journal of Medicine, July 2011).
Powerful acid-suppressing drugs like omeprazole (Prilosec) and lansoprazole (Prevacid) may interfere with the effectiveness of osteoporosis drugs like alendronate (Fosamax). A recent study reported increased hip fractures among people taking such a combination (Archives of Internal Medicine, June 13, 2011).
Is Lipitor safe enough to go over the counter? There are unconfirmed rumors that the maker of this blockbuster cholesterol-lowering drug might consider asking the FDA to allow Lipitor to be sold without a prescription.
Readers of this column have reported a wide range of side effects associated with statin drugs like Lipitor. They include debilitating muscle pain and weakness, difficulties controlling blood sugar, peripheral neuropathy, sexual dysfunction and "brain fog."
One reader warned: "I believe OTC [Lipitor] would be a mistake. So many people don't read anything on labels and will just pop a pill if they think it might help some problem for them. [There is] too much risk with this drug."
Educating the American public to use Lipitor appropriately without medical supervision could be a big challenge. Studies have shown that many people don't read labels. Determining the benefits and risks of statin-type cholesterol-lowering drugs is by no means easy, even for health professionals.