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Plavix Goes Generic

By Jessica Girdwain

As one of the best known of the big-name drugs goes generic, will prescribing undergo some changes?

Plavix, one of the most widely used brand-name prescription medications on the market, got a facelift when the patent for clopidogrel expired as of May 17. The patent expiration on the popular anticlotting drug used to prevent strokes and heart attacks opened the door for competitors to manufacture generic versions.

The good news is that these generics shouldn’t differ much from the original Plavix. “There shouldn’t be any major differences between Plavix and the generic. One would hope that the generic is equivalent to the parent compound, so the idea that the medication itself may differ in some way from one another is probably not an issue,” says Robert O. Bonow, MD, a cardiologist at Northwestern Memorial Hospital in Chicago and a spokesperson for the American Heart Association.

It comes as no surprise that when a generic enters the market, prescribing patterns shift. So far physicians haven’t been lured toward prescribing competitor drugs, such as prasugrel (Effient) and ticagrelor (BRILINTA), more frequently then Plavix, but the availability of a generic version of Plavix just might do this, according to Bonow.

“It’s quite likely we’ll see a market shift toward generic Plavix compared to the other drugs available, Bonow says. “Clinically, doctors are used to using Plavix. And yes, they may recommend a generic version because it’s cheaper.” However, physicians don’t yet know exactly how much less the generic version will cost compared with the brand name.

While generic, and therefore cheaper, versions of Plavix may offer a range of benefits, including the likelihood of increased patient adherence because of decreased costs, Richard Shlofmitz, MD, director of the cardiology department at St Francis Hospital in Roslyn, New York, points out that the power in prescribing may fall more into the hands of the insurance companies rather than physicians.

“Insurance companies may begin to advise doctors on what drug their patient needs in order to provide coverage,” Shlofmitz says. “We’re starting to see insurance companies put prior authorization in place [for certain brand-name medications]. In order for a prescription to be written out on branded antiplatelet medications, you as a doctor may be required to show that the patient adequately responds to the drug.” Those insurance requirements will become increasingly prevalent as the generic version expands. “We are still in the beginning stages of the generic and waiting to see how prescribing patterns will be affected,” Shlofmitz says.

Efficacy Concerns
Shlofmitz suggests physicians keep in mind that Plavix and its range of generics may not work for all patients. Consider the increase in platelet reactivity and genetic tests identifying whether a patient will respond to an antiplatelet drug—which some physicians, including Shlofmitz, believe is necessary for prescribing antiplatelets for the benefit of both patient and physician—and it becomes even more critical now that generic forms have expanded the market.

There is concern regarding some patients’ genetic variation that predisposes them to respond poorly to Plavix or its generics, making the drugs less effective. The idea of prescreening patients to determine whether patients respond to the medication is something physicians should consider. However, a new and controversial school of thought is emerging that suggests physicians should require routine screening for all patients before prescribing Plavix or its generics.

Shlofmitz believes that physicians should consider recommending their patients undergo a platelet reactivity test to identify Plavix nonresponders. The test examines a patient’s platelet reactivity to determine whether Plavix or its generics will offer a viable treatment. “The issue here is that Plavix is a drug that’s been on the market for a while and we use it all the time, so we assumed that everything was perfect with the medication,” he says.

But, of course, no drug is perfect. “Some people who take Plavix don’t have the enzymes they need to activate the drug, which means they aren’t deriving the maximum benefit,” he says. Forty percent of patients don’t have adequate enzyme levels, and drug activity is inhibited when they take it, according to Shlofmitz.

However, Bonow doesn’t screen his patients routinely. “For patients that have ongoing problems with the drugs, you might prescreen them,” he says. But with the generic medication coming to the market, it could change the way doctors screen patients. “There’s a fine balance. Now you have a drug that’s generic, which might lead to greater use. But because the drug is more cost-effective, we might see more testing,” says Bonow, noting that physicians should consider that generic Plavix, a less expensive formulation, might offset the cost of genetic testing.

With a measure in place to determine the drug’s efficacy, “especially with the generic coming out and more patients being potentially prescribed it, it’s more essential to show if the drug is working or not,” Shlofmitz says. Physicians should be aware that the blood test can be easily done in a doctor’s office or hospital, with results taking only five minutes. “If, as a physician, what if you don’t do it and something happens to the patient? There’s really no reason not to give this test.”

— Jessica Girdwain is a Chicago-based freelance writer who has contributed health-related articles to several national magazines.