Many doctors appear to have largely ignored a U.S. Food and Drug Administration warning to screen users of new antipsychotic drugs for high blood sugar and cholesterol because of certain health risks, according to a new study in the Archives of General Psychiatry. The findings, the researchers say, raise questions about the efficacy of warning protocols in general.

The researchers analyzed about 109,000 Medicaid patients taking second generation antipsychotic drugs, which can cause increases in blood sugar, cholesterol and significant weight gain, as well as other symptoms – significantly raising the risk of diabetes. They found that most doctors never changed their level of baseline screening for blood sugar and cholesterol, despite a warning in 2003 from the FDA and two other organizations that these antipsychotic drugs could raise the risk of diabetes in a patient population that already was at higher risk for this disease.

“The existing baseline screening and ongoing monitoring of glucose and lipid levels in these patients was already pretty low, and the FDA warning really had no impact in changing that,” says Daniel Hartung, an assistant professor of pharmacy instruction in the College of Pharmacy at Oregon State University.

Hartung says the side effects that can be caused by these new types of antipsychotic medications are not trivial. He says this patient group already has a problem with diabetes that's almost twice that of the general population.

By 2003, Hartung says, enough evidence of these problems had accumulated that the FDA, along with the American Diabetes Association and the American Psychiatric Association, issued formal statements and warnings about the issue, and recommended baseline metabolic testing and ongoing monitoring for anyone beginning these medications.

The study, which was funded by Pfizer, examined patients in California, Missouri and Oregon. It found no significant changes in the level of baseline testing for blood sugar and cholesterol. There was some movement toward one drug that posed less metabolic risk, the study found, but much of that could have been caused by the elimination in California, around the same time, of required prior authorization for that drug.

Second-generation antipsychotic drugs, such as olanzapine, aripiprazole and others, are very powerful medications and were originally developed for treatment of schizophrenia, Hartung says. They were largely prescribed at first only by psychiatrists, but their use has now expanded widely into treatment for problems such as bipolar disorder and less serious mental health problems such as depression, and they are often prescribed by general practitioners.

The study noted that individuals with serious mental illness often have a higher risk of diabetes and cardiovascular disease, and as such are already a vulnerable population. Since the new drugs can significantly increase those risks, monitoring blood sugar and cholesterol is very important, experts say.