What are the potential side effects of escitalopram (Lexapro)?

Escitalopram Side Effects

Escitalopram is generally well-tolerated with most side effects being mild to moderate and transient, but clinicians must monitor for serious adverse events including serotonin syndrome, QT prolongation (particularly with citalopram), abnormal bleeding, and sexual dysfunction. 1

Common Side Effects (≥5% incidence and twice placebo)

In Major Depressive Disorder

• Nausea (15%) - most common gastrointestinal complaint 1
• Insomnia (9%) - dose-dependent, more common at 20 mg/day (14%) versus 10 mg/day (7%) 1
• Ejaculation disorder (9% in males) - primarily ejaculatory delay 1
• Diarrhea (8%) - increases to 14% at higher doses 1
• Fatigue (5%) 1
• Sweating increased (5%) 1
• Somnolence (6%) 1
• Dizziness (5%) 1

In Generalized Anxiety Disorder

• Nausea (18%) - higher than in depression trials 1
• Ejaculation disorder (14% in males) 1
• Somnolence (13%) 1
• Insomnia (12%) 1
• Fatigue (8%) 1
• Decreased libido (7%) 1
• Anorgasmia (6% in females) 1

Additional Common Effects

• Dry mouth, constipation, decreased appetite, weakness, shaking, yawning 1

Serious Adverse Effects Requiring Immediate Attention

Serotonin Syndrome

This potentially fatal condition occurs when escitalopram is combined with other serotonergic agents, with symptoms appearing within 24-48 hours of combining medications. 2

Clinical presentation includes the triad of:

• Mental status changes - confusion, agitation, anxiety 2
• Neuromuscular hyperactivity - tremors, clonus, hyperreflexia, muscle rigidity 2
• Autonomic hyperactivity - hypertension, tachycardia, arrhythmias, tachypnea, diaphoresis, shivering, vomiting, diarrhea 2
• Advanced symptoms - fever, seizures, arrhythmias, unconsciousness leading to death 2

Contraindicated combinations include MAOIs (phenelzine, isocarboxazid, moclobemide, isoniazid, linezolid). 2

Exercise caution when combining with: tramadol, meperidine, methadone, fentanyl, amphetamines, dextromethorphan, St. John's wort, L-tryptophan, and illicit drugs (ecstasy, methamphetamine, cocaine, LSD). 2

Bleeding Risk

Abnormal bleeding can occur, especially with concomitant aspirin or NSAID use, manifesting as ecchymosis, hematoma, epistaxis, petechiae, or hemorrhage. 2

Cardiac Effects

While escitalopram has less QT prolongation risk than citalopram, SSRIs (especially citalopram) may interact with drugs that prolong the QT interval. 2

Escitalopram/citalopram have the least effect on CYP450 isoenzymes compared with other SSRIs and lower propensity for drug interactions. 2

Sexual Dysfunction

Sexual side effects are common but often underreported due to patient and physician reluctance to discuss them. 1

• Males: ejaculation disorder (12%), decreased libido (6%), impotence (2%) 1
• Females: decreased libido (3%), anorgasmia (3%) 1
• Priapism has been reported with all SSRIs 1

Discontinuation Syndrome

Escitalopram has a lower risk of discontinuation syndrome compared to shorter-acting SSRIs like paroxetine, but abrupt cessation can still cause symptoms. 2

Symptoms include: dizziness, fatigue, lethargy, general malaise, myalgias, chills, headaches, nausea, vomiting, diarrhea, insomnia, imbalance, vertigo, sensory disturbances, paresthesias, anxiety, irritability, and agitation. 2

Special Population Considerations

Neonatal Effects (Third-Trimester Exposure)

Infants exposed to SSRIs including escitalopram in the third trimester may develop neonatal adaptation syndrome. 2

Symptoms include: continuous crying, irritability, jitteriness, restlessness, shivering, fever, tremors, hypertonia, tachypnea, respiratory distress, feeding difficulty, sleep disturbance, hypoglycemia, and seizures. 2

• Onset: several hours to several days after birth 2
• Duration: typically resolves within 1-2 weeks, though may persist up to 4 weeks 2

Pediatric Patients (6-17 years)

Additional side effects in children/adolescents include: increased thirst, abnormal increase in muscle movement or agitation, nosebleed, difficult urination, heavy menstrual periods, and possible slowed growth rate requiring height/weight monitoring. 1

Elderly Patients

Escitalopram is preferred over paroxetine and fluoxetine in older adults due to favorable adverse effect profile. 2

Lower starting doses (approximately 50% of adult dose) are recommended due to increased risk of adverse drug reactions. 2

Dose-Dependent Effects

The 20 mg/day dose shows approximately twice the incidence of certain side effects compared to 10 mg/day: 1

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

Initial Adverse Effects

Anxiety or agitation can occur as an initial adverse effect of SSRIs, making it advisable to start with a subtherapeutic "test" dose. 2

Clinical Monitoring Recommendations

• Routinely inquire about sexual dysfunction as patients may be reluctant to report 1
• Monitor for serotonin syndrome symptoms within 24-48 hours after starting or increasing dose, especially when combining serotonergic drugs 2
• Monitor height and weight in pediatric patients 1
• Assess for bleeding risk, particularly with concurrent antiplatelet or NSAID use 2