Psychiatry · Year 3 · from Psychiatry
Case 1: SSRI Initiation and Management
Patient Demographics
- Age: 34 years old
- Sex: Female
- Occupation: Middle school teacher
Chief Complaint
"I've felt sad and anxious for months. I think I finally need medication."
History of Present Illness
The patient is a 34-year-old woman with a 6-month history of persistent depressed mood, anhedonia, insomnia, poor concentration, and fatigue. She also experiences significant generalized anxiety with excessive worry about work performance, her children's safety, and finances. She has tried therapy for 4 months with partial improvement in coping skills but persistent symptoms. She now wishes to try medication.
This is her first major depressive episode. She has no history of manic or hypomanic symptoms. She denies suicidal ideation. She tried St. John's Wort briefly without benefit.
She is otherwise healthy with no significant medical history. She takes no prescription medications. She is married with two children and is not planning pregnancy. She has no known drug allergies.
Mental Status Examination
Appearance: Well-groomed woman, appears tired
Behavior: Cooperative, mild psychomotor slowing
Speech: Normal rate, soft volume
Mood: "Sad and worried"
Affect: Dysphoric, anxious, constricted
Thought Process: Linear, ruminative
Thought Content: Preoccupation with work performance and family safety; no suicidal ideation
Insight: Good
Judgment: Good
Screening Measures
- PHQ-9: 16 (moderately severe depression)
- GAD-7: 14 (moderate anxiety)
Diagnosis
- Major Depressive Disorder, Single Episode, Moderate
- Generalized Anxiety Disorder
Medication Selection Discussion
Why SSRI as First-Line:
- Efficacy for both depression and anxiety
- Generally well-tolerated
- Safe in overdose
- Once-daily dosing improves adherence
SSRI Selection:
- Sertraline selected based on:
- Good evidence base for both MDD and GAD
- Favorable drug interaction profile (minimal CYP2D6 inhibition)
- Generally well-tolerated
- Once-daily dosing
- Available generically
Pharmacokinetic Teaching Points
Absorption:
- Oral bioavailability ~45%
- Food minimally affects absorption
- Can be taken with or without food
Distribution:
- Highly protein bound (~98%)
- Large volume of distribution
- Crosses blood-brain barrier
Metabolism:
- Hepatic via CYP enzymes (primarily CYP2D6, CYP3A4)
- Active metabolite (desmethylsertraline) with minimal clinical activity
- Half-life: 26 hours (allows once-daily dosing)
Elimination:
- Primarily fecal excretion of metabolites
- Steady state reached in ~1 week
- No dose adjustment for mild-moderate renal impairment
Prescribing Plan
Initial Prescription:
- Sertraline 25 mg daily for 1 week, then increase to 50 mg daily
- Take in the morning (can be activating)
- Starting low minimizes initial side effects
Patient Counseling:
Timeline:
- Side effects often occur in first 1-2 weeks, then diminish
- Antidepressant effect: Earliest improvement 2-4 weeks
- Full effect: 6-8 weeks
- Do not stop if no immediate improvement
Common Side Effects:
- Nausea (take with food, usually resolves)
- Headache (typically temporary)
- Insomnia or drowsiness (adjust timing of dose)
- Sexual dysfunction (may persist; discuss if occurs)
- Initial anxiety/activation (typically transient)
Serious Side Effects to Report:
- Worsening depression or new suicidal thoughts
- Signs of serotonin syndrome (agitation, tremor, fever, sweating)
- Easy bruising/bleeding (SSRI effect on platelets)
- Hyponatremia symptoms (elderly - confusion, weakness)
Discontinuation:
- Do not stop abruptly
- Sertraline has moderate discontinuation syndrome risk
- Gradual taper when stopping
Follow-up Plan
Week 1 (phone):
- Assess tolerability
- Check for side effects
- Confirm increase to 50 mg
Week 4 (in-person):
- Assess early response (PHQ-9, GAD-7)
- If tolerated but insufficient response, increase to 100 mg
- Target dose range: 50-200 mg
Week 8-12:
- Assess for remission
- If partial response, consider increasing dose or augmentation
- If non-response, consider switching agents