Effective but slow, with early worsening and a discontinuation syndrome
Expansion
Choice: sertraline is preferred after myocardial infarction and in most general use; citalopram and escitalopram prolong the QT and have dose limits, particularly over 65; fluoxetine is first line in children and adolescents.
Timeline: some effect within 1 to 2 weeks, full effect at 4 to 6 weeks. Continue for at least 6 months after remission, and longer with recurrent episodes.
Early cautions
- Increased anxiety and agitation in the first weeks
- A transient increase in suicidal ideation, particularly under 30. Review within 1 week in that group, and within 2 weeks otherwise
Adverse effects: gastrointestinal upset (the commonest), hyponatraemia from SIADH especially in the elderly, bleeding risk (add a proton pump inhibitor with an NSAID), sexual dysfunction, and QT prolongation with citalopram.
Interactions: NSAIDs and anticoagulants (bleeding), triptans, tramadol, linezolid, MAOIs and St John’s wort (serotonin syndrome).
Discontinuation syndrome: dizziness, electric shock sensations, insomnia, flu-like symptoms and anxiety, worst with paroxetine and venlafaxine because of their short half lives, and least with fluoxetine. Taper over at least 4 weeks.
“Start low, review early, taper slowly.”