Friday, May 24, 2013
Rimonabant and Memory Loss
My 75 year old mom is in a Rimonabant study. She has been participating for approximately 18 months. She has a history of lacunar infarction x 1. She did experience a fall from loss of control on one side of her body, but she recovered physically in a few weeks. Since she has been on this drug, her memory has been deteriorating and the neurologist associated with the study diagnosed her with Cognitive Memory Impairment a year after she had been on the study. Can this drug affect her memory and create or worsen the problem? I have read articles that it also may block a protective mechanism of the endocannabinoid system in the stroke patient. How does that system work and how is it protective?
I am aware of rimonabant, having read some studies that have been published about the drug. However, the drug is not yet FDA approved for any indication to my knowledge. With regard to possible side effects, you should consult directly with the physicians who are conducting the study. In a limited search of the web, I did see some suggestion that there may be prominent side effects from this agent. It is biologically plausible that the drug could promote the development of neurodegenerative diseases such as cognitive disorders in someone who is susceptible. This is speculation, not supported by data (to my knowledge). There have apparently been published reports that severe depression has been seen in patients, and this was reported in the press as one of the reasons why the drug was not approved by the FDA. With any new drug, careful research studies must be performed to see if it is safe, and then whether it has any benefit. The people running the study should know about the memory dysfunction, as they should be keeping careful track of side effects ("adverse events").
I do not know in detail how the endocannabinoid system works myself, so I cannot answer your question. The research that I have read shows that those taking the drug had weight loss, prevented weight gain, better lipid profiles, and perhaps reduced diabetes. The suggestion (made by investigators in the trial, as well as the company that makes the drug) is that the benefit in cardiac and stroke risk factors exceeded that expected by weight loss alone. The reduction in cardiac/stroke risk factors should result in reduced cardiac events and strokes-this is the subject of ongoing research.
Brett Kissela, MD
Assistant Professor of Neurology
Director, Neurology Residency Program
College of Medicine
University of Cincinnati