What are the potential side effects and considerations for using escitalopram (Selective Serotonin Reuptake Inhibitor - SSRI) in an older adult patient with scalp itchiness and potential neuropathic or psychogenic factors?

Escitalopram Side Effects in Older Adults

Escitalopram is generally well-tolerated in older adults, but you must be aware of specific side effects that occur more frequently in this population, particularly gastrointestinal symptoms, sexual dysfunction, and central nervous system effects that can impact falls risk and cognitive function. 1

Most Common Side Effects (≥5% and twice placebo rate)

Gastrointestinal Effects

• Nausea (15-18%) is the most common side effect and the leading cause of discontinuation 1
• Diarrhea (8%) occurs frequently but rarely leads to discontinuation 1
• Constipation (3-5%), indigestion (3%), dry mouth (3-9% dose-dependent), and abdominal pain (2%) are also reported 1

Central Nervous System Effects

• Insomnia (9-12%) is common and shows dose-dependency, occurring in 14% at 20mg/day versus 7% at 10mg/day 1
• Somnolence/drowsiness (6-13%) can increase falls risk in elderly patients 1
• Dizziness (5%) is particularly concerning in older adults due to falls risk 1
• Fatigue (5-8%) occurs frequently and may be dose-related 1

Sexual Dysfunction

• Ejaculatory delay (9-14% in males) is the most common sexual side effect 1
• Decreased libido (3-7%) affects both sexes 1
• Anorgasmia (2-6%) occurs more frequently in females 1
• Impotence (3% in males) is reported 1

Serious Adverse Effects Requiring Immediate Attention

Serotonin Syndrome

• Symptoms include tremor, diarrhea, delirium, neuromuscular rigidity, hyperreflexia, hyperthermia, autonomic instability (hypertension, tachycardia), and diaphoresis 2, 1
• Risk increases when combining escitalopram with other serotonergic agents (tramadol, triptans, other SSRIs/SNRIs, St. John's Wort, tryptophan supplements) 2, 1
• Absolutely contraindicated with MAOIs - must wait 14 days after MAOI discontinuation before starting escitalopram 2, 1

Cardiac Effects

• QT prolongation can occur, particularly at doses exceeding 20mg/day (maximum dose for patients >60 years is 20mg/day due to this risk) 2, 3
• Avoid in patients with long QT syndrome or those taking other QT-prolonging medications 2, 1

Bleeding Risk

• Increased bleeding risk, particularly when combined with NSAIDs, aspirin, or anticoagulants 1
• Monitor for bruising, petechiae, or gastrointestinal bleeding 1

Hyponatremia

• SIADH and hyponatremia occur more frequently in elderly patients 1
• Monitor sodium levels, especially in the first few weeks of treatment 1

Discontinuation Syndrome

Abrupt cessation can cause withdrawal symptoms including dizziness, fatigue, myalgias, headaches, nausea, insomnia, anxiety, irritability, and sensory disturbances 2

• Escitalopram has a 27-33 hour half-life, providing some protection against discontinuation syndrome compared to shorter-acting SSRIs like paroxetine 4
• Taper gradually when discontinuing, particularly after prolonged use 2

Dose-Dependent Side Effects

Higher doses (20mg/day) significantly increase side effect burden compared to 10mg/day: 1

• Insomnia: 14% (20mg) vs 7% (10mg) vs 4% (placebo)
• Diarrhea: 14% (20mg) vs 6% (10mg) vs 5% (placebo)
• Dry mouth: 9% (20mg) vs 4% (10mg) vs 3% (placebo)
• Somnolence: 9% (20mg) vs 4% (10mg) vs 1% (placebo)
• Increased sweating: 8% (20mg) vs 3% (10mg) vs <1% (placebo)

Special Considerations for Scalp Itchiness Context

Neuropathic Pruritus

• If scalp itchiness is neuropathic in origin (burning, tingling, paresthesias), refer to neurology or appropriate specialist for targeted treatment 2
• Escitalopram is not indicated for neuropathic pruritus; gabapentin or other neuropathic agents would be more appropriate 2

Psychogenic Pruritus

• For pruritus with psychological factors, consider psychosocial interventions, behavioral therapy, and relaxation techniques as first-line approaches 2
• SSRIs like escitalopram may have a role in psychogenic pruritus (functional itch disorder), though sertraline has more specific evidence in hepatic pruritus 2
• NB-UVB phototherapy may benefit patients with psychogenic pruritus 2

Drug-Induced Considerations

• Escitalopram itself rarely causes skin rash or pruritus, but cases have been reported 5
• If new-onset pruritus develops after starting escitalopram, consider drug-induced etiology 5

Monitoring Requirements

Assess within 1-2 weeks of initiation for: 3

• Suicidal ideation, agitation, or behavioral changes (particularly in first 24-48 hours after dose changes)
• Adverse effects tolerance
• Early signs of serotonin syndrome

Continue monitoring at regular intervals for: 3

• Therapeutic response (inadequate response by 6-8 weeks warrants treatment modification)
• Ongoing adverse effects
• Sodium levels (especially in elderly)
• Falls risk assessment

Critical Pitfalls to Avoid

• Do not use paroxetine or fluoxetine as alternatives in elderly patients - they have higher anticholinergic burden and drug interaction profiles 2, 3
• Start at 5mg daily in elderly patients, not the standard 10mg adult dose 3
• Maximum dose is 20mg/day in patients >60 years due to QTc prolongation risk 3
• Avoid combining with tramadol, triptans, or other serotonergic agents without careful monitoring 2, 1
• Do not abruptly discontinue - taper gradually to avoid withdrawal syndrome 2

Pregnancy and Breastfeeding

• Use late in pregnancy may increase risk of neonatal complications 1
• Escitalopram passes into breast milk - discuss risks/benefits with breastfeeding mothers 1
• Consider enrollment in the National Pregnancy Registry for Antidepressants (1-844-405-6185) if pregnancy occurs during treatment 1