From the Research
SSRI-induced thyrotoxicosis is a rare but recognized adverse effect that requires immediate medical attention, and management involves discontinuing the causative SSRI medication under medical supervision and switching to an alternative antidepressant from a different class, such as bupropion, mirtazapine, or a serotonin-norepinephrine reuptake inhibitor (SNRI) 1.
Key Considerations
- SSRI-induced thyrotoxicosis typically presents with symptoms like anxiety, tremors, palpitations, heat intolerance, weight loss, and insomnia.
- The mechanism likely involves serotonin's direct stimulatory effect on thyroid hormone production and release, as serotonin receptors are present on thyroid follicular cells 2.
- Patients with pre-existing thyroid disorders or autoimmune conditions may be at higher risk for this reaction and should be monitored more closely when starting SSRI therapy.
Management
- Discontinue the causative SSRI medication under medical supervision and switch to an alternative antidepressant from a different class, such as bupropion, mirtazapine, or a serotonin-norepinephrine reuptake inhibitor (SNRI) 1.
- Temporary symptomatic treatment may include beta-blockers like propranolol (20-40mg three times daily) to manage tachycardia and tremors, as supported by a study on the influence of propranolol plus methimazole on curative efficacy and thyroid function of patients with hyperthyroidism 3.
- Thyroid function tests should be monitored regularly after SSRI discontinuation, with most cases resolving within 2-8 weeks.
Important Notes
- A systematic review and meta-analysis found that SSRIs slightly decrease thyroid function, but the quality of evidence is low and the clinical magnitude of such effect is yet unclear 1.
- The American Thyroid Association guidelines for the diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis provide a comprehensive approach to managing thyrotoxicosis, including SSRI-induced thyrotoxicosis 4.