From the Guidelines
For patients on olanzapine, regular monitoring should include fasting blood glucose, hemoglobin A1c, lipid panel, complete blood count, liver function tests, and prolactin levels, as recommended by the most recent guidelines 1.
Monitoring Schedule
Initially, these labs should be checked at baseline before starting treatment, then at 12-16 weeks after medication initiation, and screened annually thereafter, as suggested by the latest standards of care in diabetes-2024 1.
- Weight and BMI should be monitored at each visit, along with blood pressure.
- Electrocardiogram (ECG) is recommended at baseline and periodically for patients with cardiovascular risk factors or if using high doses.
Rationale
Olanzapine can cause metabolic side effects including hyperglycemia, weight gain, and dyslipidemia, which necessitates glucose and lipid monitoring, as highlighted in the standards of medical care in diabetes-2020 1.
- Liver function tests are important as olanzapine may cause transaminase elevations.
- CBC monitoring helps detect rare but serious hematologic effects like neutropenia.
- Prolactin levels should be checked if symptoms of hyperprolactinemia develop, such as sexual dysfunction or menstrual irregularities.
Special Considerations
More frequent monitoring may be needed for patients with pre-existing diabetes, cardiovascular disease, or other risk factors, as emphasized in the practice parameter for the assessment and treatment of children and adolescents with bipolar disorder 1 and schizophrenia 1.
- Coordinated management of diabetes or prediabetes and serious mental illness is recommended to achieve diabetes treatment targets, as stated in the standards of medical care in diabetes-2020 1.
From the FDA Drug Label
Laboratory Tests: Monitor fasting blood glucose and lipid profiles at the beginning of, and periodically during, treatment.
The labs to check when a patient is on olanzapine are:
- Fasting blood glucose
- Lipid profiles 2
From the Research
Laboratory Tests to Monitor for Patients on Olanzapine
When a patient is on olanzapine, it is essential to monitor certain laboratory tests to prevent and manage potential side effects. The following tests should be considered:
- Fasting glucose levels: Olanzapine has been associated with increased fasting glucose levels, particularly in non-geriatric adult patients 3.
- Lipid profiles: Monitoring of fasting lipid levels, including triglycerides and cholesterol, is recommended due to the potential for olanzapine to cause significant increases in these parameters 3, 4.
- Liver function tests (LFTs): Asymptomatic increases in liver enzymes, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), are common during olanzapine treatment. However, significant liver enzyme elevations are rare but can occur 5, 6.
- Insulin sensitivity and resistance: Olanzapine may affect insulin sensitivity, and periodic oral glucose tolerance tests (OGTTs) can help assess the status of beta-cell insulin reserve in patients treated with olanzapine 4.
- Weight and body mass index (BMI): Regular monitoring of weight and BMI is crucial, as olanzapine can cause weight gain, particularly in patients under 60 years old 3, 4.
Frequency of Laboratory Tests
The frequency of laboratory tests may vary depending on individual patient factors, such as age, medical history, and concomitant medications. However, the following general guidelines can be considered:
- Baseline LFTs, fasting glucose, and lipid profiles should be obtained before initiating olanzapine treatment.
- LFTs and fasting glucose levels should be monitored regularly, particularly during the first few months of treatment.
- Lipid profiles and weight/BMI should be monitored at regular intervals, such as every 3-6 months.
- OGTTs can be performed periodically, such as every 6-12 months, to assess insulin sensitivity and beta-cell function.