Escitalopram (Lexapro)

Escitalopram (Lexapro): OverviewEscitalopram (Lexapro) is a selective serotonin reuptake inhibitor (SSRI) widely prescribed for the treatment of major depressive disorder (MDD) and generalized anxiety disorder (GAD). It is approved for use in adults and adolescents aged 12 years and older.
​Mechanism of Action
Escitalopram works by selectively inhibiting the serotonin reuptake transporter (SERT), preventing the reabsorption of serotonin into the presynaptic neuron. This action increases serotonin levels in the synaptic cleft, enhancing serotonergic neurotransmission. The enhanced serotonergic activity helps regulate mood, reduce anxiety, and improve emotional balance.
  • Escitalopram is the S-enantiomer of citalopram, giving it more potent and selective action on serotonin transporters with fewer side effects compared to racemic citalopram.
Mechanism of ActionEscitalopram works by selectively inhibiting the serotonin reuptake transporter (SERT), preventing the reabsorption of serotonin into the presynaptic neuron. This action increases serotonin levels in the synaptic cleft, enhancing serotonergic neurotransmission. The enhanced serotonergic activity helps regulate mood, reduce anxiety, and improve emotional balance.
  • Escitalopram is the S-enantiomer of citalopram, giving it more potent and selective action on serotonin transporters with fewer side effects compared to racemic citalopram.

Clinical Benefits
  1. Major Depressive Disorder (MDD):
    • Reduces symptoms of low mood, fatigue, anhedonia, and suicidal ideation.
    • Improves energy levels and overall quality of life.
  2. Generalized Anxiety Disorder (GAD):
    • Alleviates excessive worry, restlessness, and physical symptoms of anxiety (e.g., tension, fatigue).
  3. Other Off-Label Uses:
    • Obsessive-Compulsive Disorder (OCD).
    • Panic Disorder.
    • Social Anxiety Disorder (SAD).
    • Premenstrual Dysphoric Disorder (PMDD).

Dosage
  1. Starting Dose:
    • Adults with MDD or GAD: 10 mg once daily.
    • Adolescents with MDD: 10 mg once daily.
  2. Titration:
    • If needed, the dose can be increased to 20 mg daily after at least one week of treatment, based on tolerability and response.
  3. Administration:
    • Taken once daily, morning or evening, with or without food.
  4. Elderly and Hepatic Impairment:
    • Recommended starting dose: 5 mg daily.
    • Maximum dose: 10 mg daily.

Prevalence of Side Effects
  1. Common Side Effects (≥10%):
    • Nausea: Most common, particularly in the initial weeks.
    • Dry mouth.
    • Drowsiness or insomnia.
    • Increased sweating.
    • Headache.
    • Fatigue.
    • Sexual dysfunction: Includes decreased libido, anorgasmia, and delayed ejaculation.
  2. Less Common Side Effects (1–10%):
    • Diarrhea or constipation.
    • Dizziness.
    • Anxiety or restlessness (early in treatment).
    • Appetite changes (often mild weight gain).
  3. Rare but Serious Side Effects (<1%):
    • Serotonin Syndrome: Especially if used with other serotonergic drugs.
    • Hyponatremia: Primarily in elderly patients or those on diuretics.
    • QT Interval Prolongation: Risk increases with higher doses or predisposed individuals.
    • Mania or Hypomania: In patients with undiagnosed bipolar disorder.
  4. Discontinuation Syndrome:
    • Abrupt cessation can cause symptoms like dizziness, irritability, nausea, and "electric shock" sensations. A gradual taper is recommended.

Efficacy
  • Escitalopram is a first-line treatment for depression and anxiety disorders due to its high efficacy and tolerability.
  • Studies suggest it is among the most effective SSRIs, with fewer drug-drug interactions and a lower risk of side effects compared to some alternatives.