From the Guidelines
Mirtazapine does not directly cause diabetes, but it may increase the risk of developing diabetes in some individuals due to its association with weight gain and increased appetite. This antidepressant medication can lead to weight gain and increased appetite as common side effects, which indirectly contribute to diabetes risk. Studies suggest that mirtazapine can affect glucose metabolism and insulin sensitivity in some patients, as noted in the study published in Gastroenterology 1. The weight gain typically occurs during the first few weeks of treatment and may continue over time, with average increases of 1.5-2 kg over several months.
Patients taking mirtazapine should monitor their blood glucose levels regularly, especially those with pre-existing risk factors for diabetes such as family history, obesity, or metabolic syndrome. Lifestyle modifications including regular physical activity and a balanced diet are important while taking this medication to minimize weight gain. If you notice symptoms like increased thirst, frequent urination, or unexplained fatigue while on mirtazapine, consult your healthcare provider promptly. Your doctor may consider alternative antidepressants with lower metabolic impact if you're at high risk for diabetes or experiencing significant weight gain on mirtazapine.
Some key points to consider:
- Mirtazapine is associated with weight gain, which can increase the risk of developing diabetes
- Patients with pre-existing risk factors for diabetes should be closely monitored while taking mirtazapine
- Lifestyle modifications can help minimize weight gain and reduce the risk of developing diabetes
- Alternative antidepressants with lower metabolic impact may be considered for patients at high risk for diabetes or experiencing significant weight gain on mirtazapine, as discussed in the American College of Physicians guideline update 1.
From the FDA Drug Label
Metabolic and Nutritional Disorders: ... rare: gout, SGOT increased, healing abnormal, acid phosphatase increased, SGPT increased, diabetes mellitus, hyponatremia The diabetes mellitus is listed as a rare adverse reaction in the Metabolic and Nutritional Disorders section of the drug label for mirtazapine tablets 2.
- Mirtazapine may cause diabetes in rare cases. However, the exact incidence and risk factors are not specified in the label. Given the available information, it is possible that mirtazapine may contribute to the development of diabetes, but the evidence is limited to a rare adverse reaction report.
From the Research
Mirtazapine and Diabetes
- Mirtazapine is known to induce weight gain and possibly lead to exacerbation of diabetic profiles 3
- A study found that mirtazapine increased weight gain in diabetic patients, but other diabetic and lipid markers generally did not worsen during the 6-month treatment period 3
- Another study found that glucose tolerance improved under mirtazapine treatment, but insulin sensitivity was still impaired and remained significantly lower in patients compared to controls 4
Comparison with Other Antidepressants
- Selective serotonin reuptake inhibitors (SSRIs) may improve fasting blood sugar in laboratory studies and are preferable in nondiabetic depressed patients since they improve glucose regulation in the short run and may have little untoward effects in the long run 5, 6
- Noradrenergic antidepressants and tricyclic antidepressants (TCAs) may cause the metabolic situation to deteriorate in depressed DM2 patients 6
- Mirtazapine's efficacy increases up to a dose of about 30 mg and then decreases, with optimal acceptability in the lower range of its licensed dose 7