Patients perceptions of drug cost may affect how they benefit from the drug, even when receiving a placebo.
Patients’ perceptions of the cost of a drug may affect how much they benefit from the drug, even when they are receiving only a placebo, according to research from the University of Cincinnati (UC) and published in the Jan. 28 online issue of Neurology.
For the study, researchers told 12 people with Parkinson’s disease that they would receive shots of 2 formulations of the same drug-one costing $100 and one $1,500 per dose-with the second shot given after the first shot wore off. They were told that the formulations were believed to be of similar effectiveness and that the study was intended to prove that the drugs, while priced differently, were equally effective.
In reality, the participants received only a saline solution for both injections, but were told they were receiving either the "cheap” or "expensive” drug first. Before and after each shot, participants took several tests to measure their motor skills and also had brain scans to measure brain activity.
Both placebos improved motor function compared with their respective baseline. But when people received the "expensive” drug first, their motor skills improved by as much as 28% as opposed to 13% on the same test when they received the "cheap” drug.
“A very important conclusion from our results is that there exists an untapped therapeutic resource from within patients’ themselves. Harnessing such potential is both the challenge and the promise of these observations,” lead author Alberto Espay, MD, associate professor in the UC department of neurology and rehabilitation medicine and director, told FormularyWatch.
The placebo response might be stronger in people with Parkinson’s because the disease decreases the amount of dopamine in the brain and the placebo effect is known to increase the release of brain dopamine, according to Dr Espay, who endowed chair of the James J. and Joan A. Gardner Center for Parkinson’s Disease and Movement Disorders at the UC Neuroscience Institute and American Academy of Neurology fellow. Dopamine affects movement, but it also affects anticipation, motivation and response to new things.
After the study, patients were told about the true nature of the study. Of the participants, 8 said that they did have greater expectations of the "expensive” drug and were surprised at the extent of the difference brought about by their expectations. The other 4 participants said they had no expectation of greater benefits of the more expensive drug, and they also showed little overall changes.
The study was supported by the Davis Phinney Foundation for Parkinson’s.