Postmarketing surveillance of atypical antipsychotics has revealed that, in addition to the commonly reported side effect of weight gain, these medications have potentially serious metabolic side effects—specifically, altered glucose metabolism and elevated serum lipids. In addition, case reports have linked these agents with diabetic ketoacidosis (DKA), which has resulted in a number of deaths.
Although the mechanism by which atypical antipsychotics affect lipids and glucose regulation is unclear, the clinical effects have been well documented. Diabetes, weight gain, and elevated serum lipids are associated with an increased risk of cardiovascular disease, even among persons with relatively small serum lipid elevations. Psychiatric patients, particularly those with schizophrenia, have a greater risk of cardiovascular disease than the general population as a result of the higher prevalence of diabetes and cigarette smoking among persons with schizophrenia. In light of the risks associated with use of atypical antipsychotics, many have advocated for routine monitoring of weight, glucose, and lipids as the standard of care.
After an internal audit of rates of routine monitoring for patients taking atypical antipsychotics that revealed very poor current performance, the psychiatry service of the Louis Stokes Veterans Affairs Medical Center (VAMC) recommended that all patients who are given atypical antipsychotics be monitored for weight gain, elevation of serum lipids, and glucose dysregulation. Routine monitoring was introduced in September 2003.
Guidelines for monitoring these agents were developed by a multidisciplinary group that considered case reports, the results of prospective and retrospective studies, and guidelines published by the American Diabetes Association (ADA) and the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (the National Cholesterol Education Program, or NCEP). The frequencies of weight and lipid monitoring are based on NCEP guidelines. Glucose monitoring is more frequent than recommended in the ADA guidelines on the grounds that reported cases of DKA have occurred more often during the first three months of therapy. Because of the difficulty of obtaining fasting glucose measurements in the outpatient veteran population, hemoglobin A1c was selected as an indicator of glucose regulation. Because hemoglobin A1c is a measure of glucose irreversibly bound to hemoglobin over the 120-day life of a red blood cell, it is not affected by daily fluctuations, and fasting is not required. Fasting blood glucose would be a suitable substitute in settings in which fasting can be assured.
Under the monitoring schedule used at the medical center, height and weight are measured at baseline, and weight is measured at every visit (a minimum of every six months). Serum lipids are measured at baseline and every six months. Hemoglobin A1c is measured at baseline, after one month, after three months, and then every six months.
To maximize the number of patients who were monitored, a method of ordering weight measurements and laboratory tests was developed and tied to prescription order entry, which is done electronically at the VAMC. The intervention consists of an electronic order menu designed for the computerized patient record system (CPRS), which is the software used by the VAMC for all electronic medical records. When a prescriber attempts to order an atypical antipsychotic a pop-up box appears. The box contains a list of buttons containing the names of the drugs. When the drug and dosage have been selected, the box prompts the prescriber to enter baseline height and weight (the CPRS automatically calculates body mass index) and to use check boxes to select required laboratory tests. The check boxes are linked to the laboratory order menu, and the necessary blood draw is immediately ordered. If the prescriber is renewing an order, the baseline measurements that have already been collected will be displayed at the top of the box, and check boxes will appear below so that the prescriber can order follow-up laboratory tests.
The utility of this intervention will be measured by comparing rates of metabolic monitoring of patients receiving atypical antipsychotics before and after the implementation of the intervention. Through data collection from CPRS, we will be able to follow-up in a meaningful way to further demonstrate the utility of direct physician computer order entry. In addition, we expect that increased monitoring will result in earlier detection of diabetes and dyslipidemia, earlier intervention, and improved health outcomes.