Drugs with different chemical structures can provide new options, researchers say

By Bradley J. Fikes | 8 a.m. May 9, 2016

Health insurers and patients could safely save many billions of dollars annually by swapping out a more expensive drug for a less expensive generic in the same class of drugs, according to a study published Monday.

The suggestion goes beyond the common practice of substituting a generic drug for a brand-name drug with the identical active ingredient. The researchers say that in many instances, a generic with a different chemical makeup, prescribed for the same disease, could work just as well. This is called therapeutic substitution

For example, a brand-name proton pump inhibitor, used to reduce acid reflux, could be replaced with a generic proton pump inhibitor with a different active ingredient. In many cases, the benefits would be the same. To pay more for the same benefit is just excess spending, the researchers say.

Excess spending of $73 billion took place between 2010 and 2012, the study concluded. Researchers examined prescription data on 107,123 patients, using the Medical Expenditure Panel Survey from the Department of Health and Human Services.

Of the total excess spending during that period, patients paid 33 percent, or $24.6 billion, out of pocket.

The study was published in JAMA Internal Medicine. It was authored by Michael E. Johansen, M.D., of The Ohio State University in Columbus; and Caroline Richardson, M.D., of the University of Michigan, Ann Arbor. It can be found at http://j.mp/drugsubs.

The most excess money was spent on statins to lower cholesterol, with an excess expenditure of $10.9 billion; and atypical antipsychotics for mental disorders, with a $9.9 billion excess. Proton pump inhibitors to reduce stomach acid incurred an extra expense of $6.12 billion; and selective serotonin reuptake inhibitors, for depression, $6.08 billion.

“A previous study showed substantial potential savings if therapeutic substitution were introduced to Medicare Part D,” the authors stated. “In addition, a nationally representative study showed high levels of branded proton pump inhibitor (PPI) use and expenditure between 2007 and 2011 when a therapeutically equivalent generic medication was available.”

Certain classes of drugs were omitted from the analysis, including some antibiotics and respiratory drugs and testosterone. Insulin was also omitted, because no generic form is available.

The study’s cost savings estimates are correct, said Jonathan Watanabe, an assistant professor in the Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego. Watanabe wrote his doctor of pharmacy thesis on the subject.

“It’s been demonstrated in several studies that there’s a lot of money being left on the table, because we’re not using generics as effectively as we could be,” Watanabe said.

Substitution may actually improve patient health, Watanabe said. Those who have trouble affording expensive brand-name drugs are apt to fall out of compliance, losing all benefit from the drug they never take. And that may mean greater expenses down the road, if patients are hospitalized for a condition that faithful adherence to their medications could have averted.

“If we could keep them more adherent, we could reduce health system costs,” he said.

Putting therapeutic substitution into practice will require better communication between doctors and pharmacists, and systems they use need to be redesigned, said author Johansen.

“The health care systems, the medical records systems, should be more aligned toward getting the easiest, cheapest, best drug into the patient’s hands,” Johansen said.

To do that, spreading the knowledge that pharmacists have is essential, he said.