Published: May 2009
Publications
Metabolic effects of antipsychotics
Prescriber Update 30(2): 12
May 2009
Although schizophrenia itself is associated with several adverse metabolic effects it is now clear that all antipsychotics, and in particular some atypical antipsychotics, are associated with adverse effects on weight, blood glucose, and lipid concentrations. All of these adverse effects have long-term consequences in terms of life expectancy.
While the effects of antipsychotics on weight gain may be responsible for the increased risk of diabetes and hyperlipidaemia, a direct effect on glucose metabolism may also occur.
Not all atypical antipsychotics are associated with the same level of risk. Clozapine and olanzapine are considered to cause adverse metabolic effects more frequently than other agents.
Prescribers are advised to monitor all patients taking antipsychotics for adverse metabolic effects.
BPAC1 have published guidance on appropriate monitoring for patients which includes:
Weight gain
- Measure baseline weight and monthly weights for all patients prescribed atypical antipsychotics or phenothiazines including depot preparations.
- Offer dietary management for obese people (BMI > 30) or those gaining significant weight (≥ 7%) during treatment.
Lipids
- Measure baseline fasting triglycerides and total cholesterol with any antipsychotic, repeated three monthly with atypical agents for the first year of treatment.
- A full lipid profile performed annually as part of routine health.
Glucose
- Consider screening all patients with schizophrenia for diabetes particularly those with risk factors for developing diabetes and those on higher risk drugs (clozapine and olanzapine). Educate those identified to be at risk about the symptoms of diabetes.
- In all patients measure fasting glucose at baseline, at three months, and then annually. Repeat this pattern if the drug is changed. The frequency of monitoring may be increased if there are changes in fasting glucose or if risk factors change.
- In patients at high risk of developing diabetes consider monthly fasting blood glucose for the first three months and then check blood glucose three monthly for the first year followed by annually thereafter.
Patients with high baseline risk factors for diabetes should be prescribed an antipsychotic with lower risk of adverse metabolic effects where possible. In patients where adverse metabolic effects emerge, antipsychotic treatment should be reviewed and metabolic disturbances actively treated.
Reference
- http://www.bpac.org.nz/magazine/2007/february/antipsychotics.asp
