Medication And Weight Gain

They just want what's best for their patients. Yet psychiatrists Meera Narasimhan and Shilpa Srinivasan understand that determining the best course of treatment isn't always clear-cut, particularly when the treatment involves antipsychotic medications.

Until about ten years ago psychiatrists relied on a class of drugs, now known as first-generation antipsychotics (FGAs), to treat psychotic illnesses. While these medications effectively address symptoms such as hallucinations and delusions, they do not alleviate a host of cognitive and affective symptoms. FGAs are also associated with troublesome side effects that effect patients' movement including Parkinson's symptoms. Such side effects can significantly impact patients' adherence to medications on a regular basis.

With the development of second-generation antipsychotics (SGAs), psychiatrists were able to add another tool to their treatment options. And while these medications are more effective at managing symptoms of psychosis and do not impair movement, patients taking them have been found to experience significant weight gain, metabolic abnormalities, and abnormalities in lipid levels. In fact, concern over SGAs and their relationship between the development of diabetes and cardiovascular disease led to a major meeting of the minds in 2003. A consensus development conference brought together the expertise of the American Diabetes Association, the American Psychiatric Association, the American Association of Clinical Endocrinologists, and the North America Association for the Study of Obesity. 

Among the data examined at the conference were studies indicating the prevalence of obesity and diabetes to be 1.5 to two times higher in individuals with schizophrenia than the general population. Dr. Srinivasan, an assistant professor of Neuropsychiatry and Behavioral science, noted, "While medications may contribute to the risk of obesity and diabetes, there are underlying factors that can also contribute to the overall prevalence, such as a sedentary lifestyle, poor nutritional intake, and higher smoking and alcohol consumption."

"Within psychiatry it's important to be aware of and manage co-morbidity with our patients." – Dr. Shipa Srinivasan

While the final results of the study are still pending, Dr. Srinivasan highlighted the approach that was taken in the research. "When it comes to the FDA approving medications, typically a medicine is compared to a placebo. This study was different in that it compared two active medications," she said.

In three other current studies at USC, collaborations with Dartmouth Medical Center involving SGAs, patient's weight gain and other metabolic parameters are also being monitored. This careful monitoring of patients on SGAs was one of the guidelines that came out of the consensus conference. Such recommendations are useful to psychiatrists in making difficult decisions on patient medications. "What we know from the consensus panel is that there are some SGAs with a lower tendency to cause weight gain and dyslipidemia. Those may be the prudent first choices barring any other factors involved," said Dr. Srinivasan, who serves as a sub-investigator on USC’s studies. She also explained other factors that come into play. "Is the patient 'treatment naïve ?' Have they tried something else? Did they respond to it? If something has worked before, there would be a tendency to try to go back to that, unless there are health or safety factors mitigating that option," she added.

Dr. Narasimhan, who is the Principal Investigator for the current studies, states that nonadherence to antipsychotic medications is highly prevalent, with as many as 75 percent of patients becoming non-compliant by the end of the second year of treatment. "We really have to look at what a patient can tolerate and his or her preference. It's important to get our patients to collaborate with us to customize treatment," she said.

Both psychiatrists realize that their role goes beyond treating their patients' psychiatric illnesses. "Within psychiatry it's so important to be aware of and manage co-morbidity with our patients," Dr. Srinivasan said. Dr. Narasimhan agrees, "Because many of our patients don't have primary care affiliations, we are in a way becoming primary care psychiatrists," she said. Both will continue to follow their patients carefully as the industry continues to understand more about the relationship between SGAs and overall health. Dr. Narasimhan also looks to the future. "There is an urgent need to develop drugs that are efficacious with a fairly benign side-effect profile in terms of metabolic issues to improve long term clinical outcomes,” she said.

Reprinted from Connections newsletter, May 2007

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