The call to expand therapeutic substitution for brand-name drugs got louder recently thanks to a study in JAMA Internal Medicine that said that therapeutic substitution could have saved the health care system $73 billion from 2010 to 2012.
Therapeutic substitution means replacing a drug that does not have a generic equivalent with a similar drug within the same general drug class. It’s controversial, raising concerns about efficacy, drug interactions, and adverse effects. In addition, said the researchers from Ohio State University who conducted the study, most physician organizations oppose therapeutic substitution and view it as undermining physician autonomy.
The study estimates that out-of-pocket expenses for patients for branded drug overuse came to almost $25 billion in the same period.
The researchers looked at data on 107,132 people, about 62% of who reported use of any prescribed medication. The survey design included payer expenditures, demographic characteristics, prescription drug info, and self-reported medical conditions.
The drug classes with the highest excess expenditures according to the study were statins ($10.9 billion), atypical antipsychotics (also known as second-generation antipsychotics: $9.9 billion), proton pump inhibitors ($6.1 billion), selective serotonin reuptake inhibitors ($6 billion), and angiotensin receptor blockers ($5.5 billion).
Though these were the leaders, excess expenditure “was identified throughout different aspects of medicine,” accounting for 1 in 10 dollars spent on prescribed medications. “Although therapeutic substitution is controversial, it offers a potential mechanism to decrease drug costs if it can be implemented in a way that does not negatively affect quality of care,” the study states.
It can get tricky, according to Joseph S. Ross, MD, of Yale, who wrote an accompanying editorial. If a doctor prescribes Zocor, for instance, a pharmacist can automatically substitute it for the generic simvastatin.
“Where generic substitution becomes more complicated is when a prescription names a brand-name drug for which there is no FDA-approved generic, but there is an approved generic version of another drug within the same class,” Ross wrote.
State laws vary on whether pharmacists can substitute within therapeutic classes.