- Last edited on March 6, 2021
Selective Serotonin Reuptake Inhibitors (SSRI)
Primer
Selective Serotonin Reuptake Inhibitors (SSRI) are first-line agents for treatment of mood disorders and anxiety disorders. The exact agent chosen will vary depending on prescriber comfort and specific patient factors including gender, diagnosis, symptoms, and patient preference.
Mechanism of Action
- SSRIs increase serotonin (5-HT) by inhibiting the serotonin transporter (SERT) and decreasing reuptake into cells. This impacts the serotonin:receptor ratio. Homeostatic forces result in adjustments in serotonin throughout the body.
Side Effects
Common
- GI upset, headaches, dry mouth, sexual dysfunction, and weight gain may be common.
Rare
- Bleeding risks, antidepressant-induced mania/hypomania, and paradoxical reactions may occur rarely.
Hair Loss
Adverse Events
Withdrawal
See main article: Antidepressant Withdrawal (Discontinuation) Syndrome
Falls, Fractures, and Hyponatremia
- Long-term use of SSRIs is associated with an increased risk of falls and fractures that is unrelated to postural hypotension, fractures, and hyponatremia.[1]
Bleeding
See main article: SSRI and SNRI Bleeding Risks
- SSRIs can inhibit platelet aggregation via altering platelet serotonin receptors.
- This can increase the risk for gastrointestinal bleeding, and the risk may be doubled with concurrent use of nonsteroidal anti-inflammatory drugs (NSAIDs).
- Use of acid-suppressing drugs such as proton pump inhibitors (PPIs) can reduce the risk of gastrointestinal (GI) bleeding.
Suicidal Behaviours
See main article: Introduction to Antidepressants: Suicidal Ideation
- There is a risk for increased suicidal behaviour and ideation for youths on antidepressants.
Fetal
See main article: Obstetric and Fetal Pharmacology
- SSRI use late in pregnancy has been associated with an increased risk of persistent pulmonary hypertension (PPHN) of the newborn (risk is 3 in 1,000; compared to population risk of 2 in 1,000).[2]
References
1)
Kennedy, S. H., Lam, R. W., McIntyre, R. S., Tourjman, S. V., Bhat, V., Blier, P., ... & CANMAT Depression Work Group. (2016). Canadian Network for Mood and Anxiety Treatments (CANMAT) 2016 clinical guidelines for the management of adults with major depressive disorder: section 3. Pharmacological treatments. The Canadian Journal of Psychiatry, 61(9), 540-560.