Switching from brand to generic eye drops for surgical prophylaxis following cataract surgery caused no difference in endophthalmitis rates and resulted in substantial cost savings in a single-center comparison.
Take-home message: Switching from brand to generic eye drops for surgical prophylaxis following cataract surgery caused no difference in endophthalmitis rates and resulted in substantial cost savings in a single-center comparison.
By Nancy Groves; Reviewed by John A. Vukich, MD
Madison, WI-Generic and brand therapeutics-whether antibiotics, corticosteroids, and nonsteroidal anti-inflammatory drugs (NSAIDs)-were equally effective in preventing infection following cataract surgery in a single-center comparison based on 6 years of data.
The comparison also found a dramatic difference in costs for the drugs-more than $1 million less during a 3-year period in which only generic medications were used compared with an earlier 3-year period in which patients were treated with brand drugs.
The evaluation-which was not a formal, rigorous scientific study-showed that the rate of endophthalmitis was about 1 in 2,000 during both study periods, said John A. Vukich, MD, who is in private practice in Madison, WI. This rate of infection is consistent with published figures.
Given the comparable clinical efficacy and substantial cost savings, the seven ophthalmic surgeons at the ambulatory surgery center have continued to use only generic topical medications for postoperative prophylaxis since making the change 4 years ago.
“We concluded that there was no real reason at this point, based on our experience, to revert to the brand,” Dr. Vukich said. “We weren’t expecting a dramatic change, but there was no observable signal.”
The off-label use of topical antibiotics, corticosteroids, and NSAIDs to minimize the risk of endophthalmitis is common practice among cataract surgeons-with most choosing fourth-generation fluoroquinolones to obtain the broadest coverage.
Despite satisfaction with the brand eye drops they had been using, Dr. Vukich and his colleagues decided to compare generic and brand eye drops because of several factors affecting their practice environment.
First, Wisconsin state law allowed substitution of a generic for a brand-name drug.
Second, the co-payment was higher for brand-name drugs in most insurance plans.
“We were getting calls regularly from patients who were complaining, as well as from pharmacists who were asking for permission to substitute a generic,” Dr. Vukich said.
“It became a regular issue,” he said. “It was the number-one reason for calling the on-call doctor, and it was multiple times a night. Some percentage of our patients was having a second contact to confirm that what we really wanted was the brand.”
Dr. Vukich and his colleagues wondered if there was truly a difference in coverage or the clinical outcome between brand and generic drops. As a matter of due diligence, they decided to switch to generic medication for 100% of cataract surgeries starting in January 2011 and compare outcomes to data from prior cases. Vigamox (Alcon Laboratories), Nevanac (Alcon Laboratories), and Pred Forte 1% (Allergan) were replaced with ofloxacin 0.3%, ketorolac 0.5%, and prednisolone acetate.
The evaluation included 6,068 eyes that had undergone cataract surgery from March 2008 to December 2010 and 5,899 from January 2011 to August 2013.
“It wasn’t meant to be a clinical trial,” Dr. Vukich said. “It wasn’t meant to be anything other than due diligence, looking back and seeing if we made a good decision and whether there were consequences.
“In all cases, the bugs that were able to be retrieved and cultured were susceptible. Nothing grew out that was a result of inadequate coverage,” he continued. “The rates were low, and the incidence was low. We can’t do a statistical comparison, but we can say that we could see no discernible difference.”
No cases of endophthalmitis were reported during the 32-month period of brand drug use, while 1 case was reported during the subsequent period of generic medication use (0.02%).
Since the cost of medication was also a motivation for conducting the comparison, the physicians looked at the financial impact of the switch. Financial data were gathered by contacting several major pharmacies in the Madison area, including well-known chains and discount retailers, and asking for their retail price on the specified drugs.
Using data from April 2015, Dr. Vukich found that the cost per eye of the three brand drugs at four pharmacies ranged from $474 to $493. The range for the generic drugs was $154 to $215. The additional cost per eye of the three brand drugs varied from $278 to $320, translating to an average savings per eye of $301 with generic products. The cumulative savings over the 3-year period of generic medication use was $1.78 million.
While critics might find fault with the methodology, outcomes, endpoints, or other aspects of the comparison, Dr. Vukich and his colleagues stand by the findings in the context of their clinical practice.
“From our perspective, as a practical matter, we think that at a minimum it gives us no reason to second-guess the decision we made to switch to generic medications,” he said.
John A Vukich, MD
This article was adapted from Dr. Vukich’s presentation at the 2015 meeting of the American Society of Cataract and Refractive Surgery. Dr. Vukich has no relevant financial relationships.