From the FDA Drug Label
Body as a Whole: ... infrequent: ... face edema, ... Peripheral Edema 2% 1% Edema 1% 0%
Yes, edema can be caused by Mirtazapine (mirtazapine) 1.
- Peripheral Edema occurred in 2% of patients treated with mirtazapine, compared to 1% of patients treated with placebo.
- Edema occurred in 1% of patients treated with mirtazapine, compared to 0% of patients treated with placebo.
- Face edema is also listed as an infrequent adverse event.
From the Research
Yes, mirtazapine can cause edema as a side effect, as evidenced by a recent case report published in 2025 2. This antidepressant, commonly prescribed for depression and sometimes for anxiety or insomnia, has been associated with peripheral edema, particularly in the lower extremities such as the ankles and feet. The risk of edema appears to be dose-dependent, with higher doses potentially increasing the likelihood of this side effect. The mechanism behind mirtazapine-induced edema is not fully understood but may relate to its effects on serotonin and histamine receptors, which can influence fluid balance and vascular permeability. Some studies suggest that older age and female gender may be risk factors for developing edema while taking mirtazapine 3. If you develop edema while taking mirtazapine, you should not stop the medication abruptly but should consult your healthcare provider. They may recommend strategies such as:
- Elevating your legs
- Reducing salt intake
- Adjusting your medication dose
- Switching to an alternative antidepressant if the edema is bothersome or severe. It's essential to note that mirtazapine can also cause other fluid-related side effects, such as hyponatremia and syndrome of inappropriate antidiuretic hormone secretion, particularly in elderly patients 4. However, the most recent and highest-quality study on this topic is the 2025 case report, which highlights the importance of monitoring for peripheral edema in patients taking mirtazapine 2.