Generic Name

Qbrelis

Mechanism

Qbrelis (escitalopram) is a selective serotonin reuptake inhibitor (SSRI).
• Primarily inhibits the serotonin transporter (SERT) → ↑synaptic 5‑HT.
• Potency is ~50‑fold higher than citalopram, producing consistent serotonin augmentation while minimizing off‑target effects.
• Rapid therapeutic rise in CSF serotonin within 1–2 weeks, correlating with onset of antidepressant effects.

Pharmacokinetics

• Absorption: Oral bioavailability ~44 %; peak serum concentrations at 4–7 h post‑dose.
• Distribution: Large Vd (~560 L); protein binding 27–37 % (α1‑acid glycoprotein).
• Metabolism: Hepatic CYP2C19 and CYP3A4 → active metabolites (N‑hydroxylated).
• Elimination: Half‑life 27–32 h (steady state in 1–2 weeks). Excreted 30 % unchanged via urine, 70 % as metabolites.
• Special Populations:
• *CYP2C19 poor metabolizers*: ↑ plasma levels, ↑ adverse effects.
• *Hepatic impairment*: 5 mg/d advised; 10 mg/d for mild disease, 20 mg/d for severe disease.
• *Renal impairment*: No dose modification required.

Indications

• Major Depressive Disorder (MDD) – adults and adolescents ≥ 12 yrs.
• Generalized Anxiety Disorder (GAD) – adults.
• Comparative studies demonstrate efficacy in panic disorder and social anxiety disorder.

Contraindications

• Contraindications: Co‑administration with monoamine oxidase inhibitors (MAOIs) within 14 days; active QT‑prolonging agents; severe hepatic insufficiency; hypersensitivity to escitalopram.
• Warnings:
• *Serotonin syndrome* – especially with other serotonergic drugs (opioids, duloxetine, tramadol).
• *QTc prolongation* – caution with anti‑arrhythmics, antipsychotics.
• *Hyponatremia* – particularly in elderly or hyponatremic patients.
• *Suicidality* – women < 25 yrs and adolescents; monitor mood and suicidal ideation.

Dosing

• Take at the same time each day; food may reduce mild GI upset.
• Do not abruptly discontinue; taper 5–10 mg drops over 2–4 weeks to mitigate withdrawal.

Adverse Effects

Common (≥10 %)
• Nausea, dry mouth, insomnia, somnolence, fatigue, sexual dysfunction, dizziness.

Common (1–10 %)
• Weight change, headache, increased sweating, constipation, tremor.

Serious (≤1 %)
• Serotonin syndrome (hyperthermia, tremor, rigidity).
• QTc prolongation → torsades de pointes.
• Hyponatremia (especially in elderly).
• Severe hypersensitivity or anaphylaxis.
• Suicide ideation → emergent evaluation.

Monitoring

• Baseline:
• Psychiatric history, suicidality assessment.
• EKG if QTc‑prolonging agents are used.
• Serum electrolytes (Na⁺, K⁺).
• Liver and renal function tests.
• Ongoing (on taper/extension) :
• Mood and suicidal ideation at each visit.
• Weight, BMI, fasting glucose if comorbid diabetes.
• Electrolytes if hyponatremia suspected.
• QTc if concomitant QT‑prolonging drugs introduced.

Clinical Pearls

• Steady‑state achievement: 1–2 weeks; tapering beyond 4 weeks may increase risk of relapse.
• CYP2C19 phenotyping is valuable for individualized dosing; poor metabolizers may require 5 mg/day maintenance.
• Drug‑drug interactions: Avoid potent CYP2C19 inhibitors (clopidogrel, omeprazole) or co‑administer with selective MAO‑A inhibitors; overlapping serotonergic agents magnify alertness for serotonin syndrome.
• Sexual dysfunction: Consider switching to tricyclic or mirtazapine if intolerable.
• Pregnancy & Lactation: Category D; risk vs benefit must be weighed; fetal serotonin syndrome is a concern with neonatal exposure.
• Once‑daily dosing promotes adherence; tablets can be split for under‑dosing in mild cases.

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• *Prepared for medical students and healthcare professionals seeking concise, SEO‑friendly reference on the pharmacology of Qbrelis (escitalopram).*