From the Guidelines
Mirtazapine can increase the risk of weight gain, which may indirectly affect glucose levels and contribute to the development of diabetes or worsen existing diabetes. As noted in a recent review on obesity management in adults 1, many commonly used medications, including antidepressants like mirtazapine, are associated with weight gain. This weight gain can increase the risk of weight-related complications, including cardiovascular disease, diabetes, and hepatic steatosis. Some key points to consider when prescribing mirtazapine include:
- The medication's potential to cause weight gain, which may be more pronounced at lower doses due to its antihistamine effects
- The importance of monitoring weight trajectory and counseling patients on lifestyle modifications to mitigate weight gain
- The potential benefits of adjunctive therapies like metformin or topiramate to counteract weight gain, although their use would depend on individual patient factors and the presence of other health conditions
- The need for patients with diabetes or prediabetes to closely monitor their blood glucose levels when starting or adjusting mirtazapine doses, as the medication may contribute to insulin resistance or exacerbate existing glucose metabolism issues.
From the Research
Mirtazapine's Effect on Glucose Levels
- Mirtazapine may affect glucose levels, as studies have shown mixed results regarding its impact on glucose metabolism 2, 3, 4, 5, 6.
- A study published in the Journal of Clinical Psychopharmacology found that mirtazapine increased weight gain in diabetic patients, but did not worsen diabetic and lipid markers over a 6-month treatment period 2.
- Another study published in Experimental and Clinical Endocrinology & Diabetes found that glucose tolerance improved under mirtazapine treatment in depressed inpatients, but insulin sensitivity remained impaired compared to healthy controls 3.
- A proof-of-concept clinical trial published in JCI Insight found that mirtazapine increased hunger and appetite for sweets, and shifted energy substrate partitioning towards carbohydrate substrate preference in healthy men 4.
- An animal study published in Animals found that mirtazapine reduced adipocyte hypertrophy and increased glucose transporter expression in obese mice, leading to lower insulin levels and improved glucose tolerance 5.
- A study published in the Iranian Journal of Basic Medical Sciences found that mirtazapine may show anti-hyperglycemic effects by decreasing GLUT2 through altering leptin and galanin expression in the liver of type 1 diabetic rats 6.
Key Findings
- Mirtazapine may increase weight gain and appetite, but its effect on glucose levels is still unclear 2, 3, 4.
- Mirtazapine may improve glucose tolerance and insulin sensitivity in some cases, but more research is needed to confirm this 3, 5, 6.
- The mechanisms by which mirtazapine affects glucose metabolism are complex and involve multiple pathways, including leptin and galanin expression 6.