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CANONICAL MONOGRAPH [11.2] • ID: TIP-MED-000206

1. Escitalopram Oxalate

2. Pharmacological Class: Selective Serotonin Reuptake Inhibitor (S-Enantiomer of Citalopram—Most Selective SSRI) • 3. Therapeutic Category: CNS & Psychiatric Medicines (Ch 11)

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4. Clinical Overview & Verified Formulation Identity

Generic Name & Identifier:
Escitalopram Oxalate
Code: [11.2] | Stable ID: TIP-MED-000206
Verified Indian Market Brands / Status:
Representative Indian Market Examples (Edition 2.7 Ch 11 [11.2], p. 140): Nexito (Sun Pharma), Cipralex (Lundbeck), Stalopam (Lupin), Feliz-S (Torrent), Rexipra (Intas); In FDC with Clonazepam (Short-term only!): Nexito-Plus, Stalopam-Plus — Strengths & Forms: Oral Film-Coated Scored Tablets: 5 mg, 10 mg, 15 mg, 20 mg
9. Dosage Forms & Strengths:
Oral Film-Coated Scored Tablets: 5 mg, 10 mg, 15 mg, 20 mg
Route: Oral / Parenteral / Topical as specified by formulation
Indian Regulatory Schedule & NLEM Status:
Schedule H Prescription Drug • NLEM 2022 Core Essential Medicine
True

5 & 6. Mechanism of Action & Pharmacodynamics

Pure active S-(+)-enantiomer of racemic Citalopram; binds with highest selectivity among all SSRIs to both the primary orthosteric site and an allosteric modulatory site on the presynaptic Serotonin Transporter (SERT / SLC6A4), blocking 5-HT reuptake into presynaptic neurons. Chronic elevation of synaptic 5-HT downregulates somatodendritic 5-HT1A autoreceptors and stimulates hippocampal BDNF neuroplasticity over 2–4 weeks.

8. Therapeutic Indications

10. Dosage and Administration (Educational Reference Summary)

Dosing & Clinical Context: Adults: Start 10 mg orally once daily; may increase after >=1 week to maximum 20 mg once daily. Elderly (>65 yr), hepatic impairment, or CYP2C19 poor metabolizers: Strict maximum 10 mg once daily (due to QTc prolongation risk).
Administration & Timing: Oral; once daily in the morning or evening, with or without food.

11 & 13. Contraindications, Precautions and Warnings

🚫 11. Contraindications:
  • Concomitant MAO Inhibitors (Selegiline, Rasagiline, Linezolid) or within 14 days of stopping an MAOI — fatal Serotonin Syndrome
  • Known congenital Long QT Syndrome or concomitant QT-prolonging drugs (Pimozide)
⚠️ 13. Precautions and Warnings:

Maximum 10 mg once daily in mild-to-moderate hepatic impairment.

7, 12, 14–18. Detailed Pharmacokinetics, Interactions, Special Populations & Counselling

7 & 16. Pharmacokinetics (ADME) & Renal / Hepatic Considerations

7. Pharmacokinetics (Absorption, Distribution, Metabolism, Excretion): Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.

16a. Renal Considerations: No adjustment in mild-to-moderate renal impairment; use caution in CrCl < 20 mL/min.

16b. Hepatic Considerations: Maximum 10 mg once daily in mild-to-moderate hepatic impairment.

12 & 14. Adverse Effects & Drug Interactions
12. Adverse Effects:
  • Initial transient nausea, insomnia or somnolence, and increased anxiety during first 1–2 weeks
  • Sexual dysfunction (anorgasmia, delayed ejaculation, decreased libido — via 5-HT2A/2C stimulation)
  • SIADH-induced hyponatraemia (especially in elderly patients or those on thiazide diuretics)
  • Dose-dependent QTc prolongation (max 20 mg/day in adults, 10 mg/day in >65 yr)
14. Drug Interactions:
  • MAOIs, Linezolid, Tramadol, Triptans, Lithium, St. John's Wort: Serotonin Syndrome (clonus, hyperthermia, agitation, autonomic instability)
  • NSAIDs (Diclofenac), Aspirin, Clopidogrel, Warfarin: SSRIs deplete platelet serotonin (5-HT) stores and double the risk of upper GI bleeding
  • Omeprazole / Esomeprazole (CYP2C19 inhibitors): increase Escitalopram plasma concentration by ~50%
  • QT-prolonging agents (Ondansetron, Macrolides, Antipsychotics): additive dose-dependent QTc prolongation
15, 17 & 18. Special Populations, Clinical Monitoring & Patient Counselling

15. Use in Special Populations (Pregnancy, Lactation, Paediatrics, Geriatrics): Evaluate maternal-foetal benefit-risk ratio, paediatric mg/kg ceiling, and geriatric renal function prior to prescribing.

17. Clinical & Laboratory Monitoring: Monitor clinical response, baseline renal/hepatic parameters, and relevant serum biomarkers.

18. Patient Counselling & Storage:
  • Full mood improvement takes 2–4 weeks, although sleep and appetite may improve within the first week — continue taking daily as prescribed.
  • Do not stop suddenly; taper gradually over 2–4 weeks to avoid SSRI discontinuation symptoms (dizziness, electric-shock paraesthesia).
  • Monitor closely for any worsening mood or suicidal ideation during the first 2–4 weeks in young adults.

Storage & Dispensing Notes: Store below 30°C.

Visual Pharmacology Illustration (PLATE-8.6)

PHARMACODYNAMICS: AGONISTS, ANTAGONISTS, POTENCY (EC50) VS EFFICACY (Emax) & TI GRADED LOG DOSE–RESPONSE CURVES Log [Drug Concentration / Dose] → % Maximal Effect (E / Emax) Full Agonist (α = 1) + Competitive Antagonist (↑EC50, Same Emax) Partial Agonist (0 < α < 1) + Non-Competitive Antagonist (↓Emax) • Potency = Dose required for 50% effect (EC50 / ED50; horizontal axis) • Efficacy = Maximum ceiling effect achievable (Emax; vertical axis) Clinical Rule: Efficacy (Emax) is clinically more important than Potency. 4 MAJOR RECEPTOR SUPERFAMILIES & THERAPEUTIC INDEX 1. Ligand-Gated Ion Channels (Ionotropic — Milliseconds): GABA_A (Benzodiazepines), Nicotinic AChR, NMDA, 5-HT3 (Ondansetron) 2. G-Protein Coupled Receptors (GPCR / 7-TM — Seconds): Gs (↑cAMP: β1, β2), Gi (↓cAMP: α2, M2, Opioid), Gq (↑IP3/DAG/Ca2+: α1, M1/M3, AT1) 3. Enzyme-Linked / Receptor Tyrosine Kinases (Minutes–Hours): Insulin receptor (PI3K/Akt → GLUT4 translocation), EGFR, VEGFR 4. Intracellular / Nuclear Receptors (Hours–Days, Gene Transcription): Corticosteroids (Prednisolone), Thyroid (T3/T4), Vitamin D, PPAR-γ THERAPEUTIC INDEX (TI = TD50 / ED50) & NTI MONITORING • Wide TI (Safe): Penicillins, Paracetamol (at normal dose), PPIs • Narrow Therapeutic Index (NTI, TI < 2 — Requires TDM): Warfarin (INR), Digoxin, Lithium, Phenytoin, Vancomycin, Aminoglycosides
Figure 8.6: Pharmacodynamic receptor occupancy, intrinsic activity (alpha), Competitive vs Non-Competitive Antagonism, Potency (EC50) vs Efficacy (Emax), and Therapeutic Index (TI = TD50 / ED50).

19. Authoritative References & Source Traceability

Primary Reference Record: Indian Pharmacopoeia (IP 2026) • NLEM 2022 (MoHFW) • CDSCO Approved Prescribing Information

Verification Portals: Indian Pharmacopoeia Commission (IPC) • CDSCO (India Jurisdiction) • NCBI Bookshelf • DailyMed (US FDA Label Reference)

Last Reviewed Date: 2026-11-08 • Related Study Guide: Epilepsy & Seizure Disorders ASM Guide →