From the FDA Drug Label
Patients starting treatment with olanzapine should undergo fasting blood glucose testing at the beginning of treatment and periodically during treatment. Olanzapine-treated patients had a greater mean HbA1c increase from baseline of 0. 04% (median exposure 21 days), compared to a mean HbA1c decrease of 0.06% in placebo-treated subjects (median exposure 17 days).
- Olanzapine does not lower A1C levels.
- In fact, olanzapine-treated patients had a greater mean HbA1c increase from baseline compared to placebo-treated subjects 1.
From the Research
Zyprexa (olanzapine) does not lower A1C levels; in fact, it typically raises them. Olanzapine is an atypical antipsychotic medication that is associated with metabolic side effects including weight gain, increased blood glucose levels, and worsening glycemic control. Studies show that patients taking Zyprexa often experience an increase in their A1C levels over time, which can be particularly problematic for individuals with diabetes or prediabetes. This effect occurs because olanzapine can cause insulin resistance and impair glucose metabolism through several mechanisms, including effects on hypothalamic regulation of appetite and direct effects on pancreatic beta cells 2.
Some key points to consider:
- Olanzapine treatment is associated with tolerability issues such as metabolic adverse effects, including weight gain, increase in blood glucose, triglycerides, and total cholesterol levels 3.
- The use of second-generation antipsychotics, including olanzapine, has been associated with metabolic changes, and long-term follow-up is necessary to detect clinically relevant impairment in metabolic parameters 4.
- Metformin may safely assist olanzapine-treated patients in body weight and carbohydrate metabolism control, although it did not improve the lipid profile and the Hb1c levels in one study 5.
If you are concerned about medication effects on blood glucose control, it's essential to discuss this with your healthcare provider. For patients taking Zyprexa who have diabetes or are at risk, regular monitoring of blood glucose levels is recommended, and additional diabetes medications may be needed to counteract these effects. Alternative antipsychotic medications with lower metabolic risks might be considered if glycemic control becomes problematic.