Generic drugs are the same as a name brand. The only difference is that a generic company does not research or clinical trials and since the product is outside patent, they only have the cost of manufacturing, so costs are lower and the product is cheaper.

Yet we are increasingly in a precautionary principle world, in everything from vaccines to food, so it is little surprise that patients prefer name brand drugs more. Though large pharmaceutical companies are being attacked in a culture war, they are still considered more trustworthy than a generic, which most people equate with lower quality materials.

But even with post-transplant drugs, there is no difference yet with it comes to generic formulations of tacrolimus, a drug used to lower the risk of organ rejection, patients prefer a name brand even though more than 70 percent of tacrolimus dispensed is generic--with no consistent negative reports. 

The findings were presented by lead investigator Rita Alloway, PharmD, UC research professor of medicine and director of transplant clinical research within the UC Department of Internal Medicine, and her study collaborators at the 2015 American Transplant Congress annual meeting in Philadelphia.

Funded by the U.S. Food and Drug Administration (FDA), the study was a prospective, blinded, six-way crossover study in kidney and liver transplant patients. It tested whether the two most disparate generics, based on potency, purity and dissolution ("Generic Hi" and "Generic Lo"), are bioequivalent to the drug tacrolimus (Prograf) in stable transplant patients.

The researchers analyzed a total of 70 patients who were transplanted at either University of Cincinnati Medical Center or The Christ Hospital (Cincinnati) transplant programs. Patients were given brand name tacrolimus or one of two generic versions.

"We found there to be essentially no difference in the formulations between the generics and brand-name version," says Alloway. "In other words, if you were on brand and switched to generic--and you take your medication as instructed--there should be no clinical consequence."

To analyze drug levels and pharmacokinetics as well as pharmacogenetics, Alloway collaborated with Uwe Christians, MD, PhD, professor of anesthesiology at the University of Colorado, and Sander Vinks, PharmD, PhD, UC professor of pediatrics and director of the Division of Clinical Pharmacology at Cincinnati Children's Hospital Medical Center.

"Drs. Christians and Vinks provided expertise in tacrolimus level analysis and pharmacokinetic-pharmacogenetic data analysis," says Alloway. "The study design incorporated the most sensitive and specific tacrolimus level analysis while evaluating different methods of bioequivalence data analysis."

Alloway and team will continue this important research through an FDA-funded study of patients who are at risk of experiencing lower concentrations and subsequent rejection episodes because they have been shown to require larger doses of tacrolimus to attain therapeutic blood concentrations.

Those data, Alloway says, "will allow us to characterize unique factors which may affect tacrolimus levels to identify if formulation has an effect in this enriched population."

Prograf (tacrolimus) is manufactured by Astellas Pharma Inc. Alloway has received clinical research support from and has served on the advisory board to Astellas. She also reports receiving clinical research grants from Novartis, Veloxis, Takeda, Onyx, GSK, Prolong, Bristol-Myers Squibb, Chiltern and Sanofi. She has served on the advisory boards of Veloxis, Sanofi and Amgen.