Starting Dose and Timing for SSRIs in Adult Anxiety Disorders
For typical adults with anxiety disorders, start escitalopram at 10 mg once daily or sertraline at 25-50 mg once daily, administered in the morning or evening with or without food, and increase doses gradually at 1-2 week intervals as tolerated. 1, 2
Initial Dosing Strategy
Escitalopram (Lexapro)
- Start at 10 mg once daily for generalized anxiety disorder in adults 1
- Can be taken morning or evening, with or without food 1
- If dose escalation needed, increase to 20 mg after a minimum of 1 week 1
- Consider starting at 5-10 mg daily as a "test dose" to minimize initial anxiety or agitation that can occur with SSRIs 3
Sertraline (Zoloft)
- Start at 25 mg once daily for panic disorder, PTSD, and social anxiety disorder 2
- After one week, increase to 50 mg once daily 2
- For major depressive disorder and OCD, can start directly at 50 mg once daily 2
- Can be taken morning or evening 2
Dose Titration Timeline
The key principle is gradual escalation to minimize side effects while achieving therapeutic benefit:
- Sertraline: Increase by 25-50 mg increments every 1-2 weeks as tolerated, targeting 50-200 mg/day 4, 3
- Escitalopram: Increase by 5-10 mg increments every 1-2 weeks, targeting 10-20 mg/day 3
- Do not change doses at intervals less than 1 week given the 24-hour elimination half-life 2
The rationale for starting low is that initial adverse effects of SSRIs can include anxiety or agitation, making a subtherapeutic "test dose" advisable 4
Expected Response Timeline
Patients must understand that SSRI response follows a logarithmic pattern:
- Week 2: Statistically significant improvement may begin 4, 3
- Week 6: Clinically significant improvement expected 4, 3
- Week 12 or later: Maximal therapeutic benefit achieved 4, 3
Do not abandon treatment prematurely - full response may take 12+ weeks, and treatment should continue for several months beyond initial response 4, 3
Critical Monitoring Considerations
Common Side Effects (First Few Weeks)
Most adverse effects emerge within the first few weeks and typically resolve with continued treatment 4, 3:
- Nausea, diarrhea, dry mouth, heartburn
- Headache, dizziness
- Somnolence or insomnia
- Sexual dysfunction
- Nervousness, tremor
Serious Warning
All SSRIs carry a boxed warning for suicidal thinking and behavior, with pooled absolute rates of 1% versus 0.2% for placebo 3. Monitor closely, especially in the first months and following dose adjustments 3.
Special Considerations for Drug Selection
Escitalopram and sertraline are preferred first-line agents due to:
- Established efficacy and favorable side effect profiles 3
- Lower risk of discontinuation symptoms compared to paroxetine 3
- Escitalopram has the least effect on CYP450 isoenzymes, resulting in lower propensity for drug interactions 4
Avoid paroxetine as it has higher risk of discontinuation syndrome and potentially increased suicidal thinking compared to other SSRIs 4
When to Adjust Treatment
If inadequate response after 8-12 weeks at therapeutic doses:
- Switch to a different SSRI (e.g., sertraline to escitalopram or vice versa) 3
- Consider adding cognitive behavioral therapy if not already implemented 3
- Combination treatment (CBT + SSRI) provides superior outcomes for moderate to severe anxiety 3
Important Pitfalls to Avoid
- Do not escalate doses too quickly - allow 1-2 weeks between increases to assess tolerability and avoid overshooting the therapeutic window 3
- Higher doses do not necessarily mean better response - it is not clear that dose is related to magnitude of response, and higher doses can be associated with more adverse effects 4
- Never combine with MAOIs - at least 14 days must elapse between discontinuation of an MAOI and initiation of SSRI therapy 1
- Gradual discontinuation is essential - abrupt cessation can cause discontinuation syndrome, particularly with shorter half-life SSRIs like sertraline 4