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MEDICINE MONOGRAPH CODE: [11.19] ID: TIP-MED-000223

Paroxetine Hydrochloride (Controlled-Release SSRI)

Active Ingredient / Scientific Identity: Paroxetine Hydrochloride • Class: Selective Serotonin Reuptake Inhibitor (SSRI with Mild Anticholinergic Activity)

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THE INDIAN PHARMACIST — Educational Reference Sheet
Profile: Paroxetine Hydrochloride (Controlled-Release SSRI) ([11.19] | ID: TIP-MED-000223) • Last Reviewed: 2026-11-10
Source URL: https://theindianpharmacist.com/medicine/11-19-paroxetine-hydrochloride-controlled-release-ssri/
Generic / Entity NameParoxetine Hydrochloride (Controlled-Release SSRI) ([11.19])
Verified Indian Brands / RefGeneric Compendial Entry (No Commercial Brand Claimed)
Pharmacological ClassSelective Serotonin Reuptake Inhibitor (SSRI with Mild Anticholinergic Activity)
Available Dosage FormsControlled-Release (CR) Tablet: 12.5 mg, 25 mg, 37.5 mg; Immediate-Release Tablet: 10 mg, 20 mg, 30 mg, 40 mg.
Regulatory ClassificationSchedule H Prescription Drug (To be sold by retail on the prescription of a Registere
Key Warning & Review DateRenal: eGFR <30 mL/min: Start at 10 mg IR or 12.5 mg CR once daily; do not exceed 40 mg IR or 50 mg CR. • Hepatic: Severe hep
Reviewed: 2026-11-10
Safety Matrix:⚖️ Legal Status: Schedule H Prescription Drug (To be sold by retail o✔️ Standard Clinical Dispensing Precautions

1. Clinical & Scientific Overview

Paroxetine Hydrochloride (Controlled-Release SSRI) (TIP-MED-000223, Reference Code [11.19]) is classified under CNS & Psychiatric Medicines (Ch 11) as a Selective Serotonin Reuptake Inhibitor (SSRI with Mild Anticholinergic Activity). Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug (To be sold by retail on the prescription of a Registered Medical Practitioner only — Drugs Rules 1945).

Verified Indian Market Examples / Compendial Status:
Representative Indian Market Examples (Edition 2.7 Ch 11 [11.19], p. 149): Pari, Paxidep-CR, Pexep-CR, Panex — Strengths & Dosage Forms: Controlled-Release (CR) Tablet: 12.5 mg, 25 mg, 37.5 mg; Immediate-Release Tablet: 10 mg, 20 mg, 30 mg, 40 mg.
Representative Indian Market Examples (Edition 2.7 Ch 11 [11.19], p. 149): Pari, Paxidep-CR, Pexep-CR, Panex — Strengths & Dosage Forms: Controlled-Release (CR) Tablet: 12.5 mg, 25 mg, 37.5 mg; Immediate-Release Tablet: 10 mg, 20 mg, 30 mg, 40 mg.
Dosage Forms & Available Strengths:
Controlled-Release (CR) Tablet: 12.5 mg, 25 mg, 37.5 mg; Immediate-Release Tablet: 10 mg, 20 mg, 30 mg, 40 mg.
Routes: Oral / Parenteral / Topical as specified by formulation

3. Mechanism of Action & Pharmacodynamics

Potent selective presynaptic 5-HT reuptake inhibitor with weak muscarinic receptor antagonism and potent CYP2D6 autoinhibition.

4. Therapeutic Indications & Evidence-Supported Uses

  • Major depressive disorder
  • social anxiety disorder
  • panic disorder
  • generalised anxiety disorder
  • post-traumatic stress disorder (PTSD)

🇮🇳 Jurisdiction & Indication Note: Indications and schedules reflect Indian compendial and regulatory records (CDSCO / Indian Pharmacopoeia & NFI / NLEM 2022). Where international reference labels (US FDA DailyMed / NCBI StatPearls) are cited for pharmacokinetic or mechanistic parameters, international approvals do not automatically imply CDSCO approval in India.

5. Educational Dosage Context, Formulations & Administration

Educational Dosing & Regimen Summary: Adult: Immediate-Release: Start 20 mg once daily (Panic: start 10 mg/day); max 50-60 mg/day. Controlled-Release (CR): Start 12.5-25 mg once daily; max 62.5 mg/day (Elderly: max 40 mg IR or 50 mg CR). • Paediatric: Not recommended in children and adolescents <18 years (increased risk of suicidal behaviour and hostility).

Administration & Meal Timing: See Administration & Counselling below. | Standard clinical schedule per indication.

6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment

Absorption & Disposition:
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Metabolism & Biotransformation:
Renal: eGFR <30 mL/min: Start at 10 mg IR or 12.5 mg CR once daily; do not exceed 40 mg IR or 50 mg CR. • Hepatic: Severe hepatic impairment: Start at 10 mg IR or 12.5 mg CR daily; max 40 mg/day.
Elimination & Renal Adjustment:
Renal: eGFR <30 mL/min: Start at 10 mg IR or 12.5 mg CR once daily; do not exceed 40 mg IR or 50 mg CR. • Hepatic: Severe hepatic impairment: Start at 10 mg IR or 12.5 mg CR daily; max 40 mg/day.
Hepatic Impairment Considerations:
Renal: eGFR <30 mL/min: Start at 10 mg IR or 12.5 mg CR once daily; do not exceed 40 mg IR or 50 mg CR. • Hepatic: Severe hepatic impairment: Start at 10 mg IR or 12.5 mg CR daily; max 40 mg/day.

7. Contraindications, Precautions & High-Risk Warnings

Contraindications & Red-Flag Precautions:
  • Contraindications: Concomitant MAOIs, Linezolid, Thioridazine, Pimozide; pregnancy (first-trimester cardiac teratogenicity risk). • Precautions: Highest incidence of severe SSRI discontinuation syndrome (electric-shock paraesthesias, vertigo, rebound anxiety) due to short half-life (~21 h) and lack of active metabolites; causes weight gain and sedation.

Key Clinical Precautions: Renal: eGFR <30 mL/min: Start at 10 mg IR or 12.5 mg CR once daily; do not exceed 40 mg IR or 50 mg CR. • Hepatic: Severe hepatic impairment: Start at 10 mg IR or 12.5 mg CR daily; max 40 mg/day.

8. Adverse Effects Profile

Common & Mechanism-Related Adverse Effects:
  • Somnolence, weight gain, dry mouth, constipation, sweating, sexual dysfunction.
  • Severe withdrawal syndrome on missed doses, SIADH hyponatraemia, serotonin syndrome.
Serious / Dose-Limiting Adverse Effects:
  • Monitor for severe hypersensitivity, organ toxicity, or dose-limiting adverse events.

9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions

  • Potent CYP2D6 inhibitor: abolishes Tamoxifen efficacy in breast cancer (CONTRAINDICATED with Tamoxifen); elevates Metoprolol, Atomoxetine, TCAs, Risperidone; NSAIDs/Aspirin -> GI bleeding

10. Clinical Monitoring, Patient Counselling & Storage

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

Pharmacist Patient Counselling Points:

  • Patient Counselling Checklist: Swallow CR tablets whole (do not crush or chew); never miss doses or stop suddenly (causes dizziness and electric-shock sensations; requires slow taper over weeks).
  • Meal & Clock Timing Instruction: See Administration & Counselling below. (Standard clinical schedule per indication.)
  • Missed Dose Protocol: Take as soon as remembered unless close to next scheduled dose; never double the dose.
  • Geriatric Dispensing Pearl: Schedule: Schedule H | NLEM 2022: Non-NLEM | Compendia: IP 2026 / NFI 7th Ed 2026 / CDSCO Schedule H / BNF 90th Ed

Storage, Stability & Dispensing Safeguards: Store below 25°C–30°C in original moisture- and light-resistant packaging out of reach of children. Available forms: Controlled-Release (CR) Tablet: 12.5 mg, 25 mg, 37.5 mg; Immediate-Release Tablet: 10 mg, 20 mg, 30 mg, 40 mg.

11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)

THE 12-STEP ORAL DRUG JOURNEY THROUGH THE HUMAN BODY (LADME) Note: IV bolus enters Step 6 directly (F = 100%); Sublingual & Transdermal routes bypass Step 4–5 Portal First-Pass Metabolism 1. Oral Administration • Tablet / Capsule swallowed • Gastric emptying to duodenum pH 1.5–3.5 (Stomach) 2. Disintegration & Dissolution • Tablet breaks into granules • API dissolves in GI fluid Noyes-Whitney Dissolution Rate 3. GI Epithelial Absorption • Crosses intestinal villi • Passive / Active / P-gp efflux Small Intestine (Large Surface Area) 4. Portal Circulation • Mesenteric veins → Portal vein • Delivers blood to liver sinusoids Pre-systemic Venous Conduit 5. First-Pass Metabolism • Gut & hepatic CYP450 extraction • High: GTN, Propranolol, Morphine Determines Bioavailability (F = f_a × (1-E_H)) 6. Systemic Circulation • Hepatic vein → IVC → Heart • Unbound vs Albumin-bound drug Only FREE drug is active 7–8. Tissue Distribution (Vd) • Capillary permeation to organs • Blood-Brain & Placental barriers Vd = Dose / C_0 (L or L/kg) 9. Target Site of Action • Receptors (GPCR, Ion channel) • Enzymes & Carrier Transporters Pharmacodynamic Effect (E_max, EC50) 10. Hepatic Biotransformation • Phase I (CYP450 Oxidation/Hydrolysis) • Phase II (Glucuronidation/Sulfation) Converts lipophilic drug → hydrophilic metabolite 11. Renal & Biliary Elimination • Nephron: Filtration + Secretion − Reabsorption • Biliary excretion & Enterohepatic recycling Total Clearance CL_tot = CL_renal + CL_hepatic 12. Excretion from the Body • Urine (Primary polar metabolite route) • Bile/Faeces, Expired Air, Sweat, Milk Elimination Half-Life t1/2 = (0.693 × Vd) / CL
svg-v339-01-adme-12-step-journey — 8.1 Complete 12-Step Journey of an Orally Administered Drug (ADME): Figure 8.1: The 12-step physiological journey of a typical orally administered solid dosage form through Liberation, Absorption, Distribution, Metabolism, and Excretion (LADME). Note: Parenteral (IV), sublingual, and inhalational routes bypass gastrointestinal absorption and/or hepatic first-pass metabolism.

12. Authoritative References, Regulatory Sources & Editorial Disclaimer

Primary Compendial & Guideline Reference: Indian Pharmacist Desk Reference — Professional Edition 2.7 (2026–27) • Ch 11 [11.19] (p. 149)

Official Verification Portals: Indian Pharmacopoeia Commission (IPC) & National Formulary of India (NFI) • Central Drugs Standard Control Organization (CDSCO) • Ministry of Health & Family Welfare — NLEM 2022 • NCBI Bookshelf / StatPearls Pharmacology Reference • DailyMed (US FDA Official Prescribing Reference)

Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: HANDBOOK_SOURCE_CONTENT

Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.

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Educational Reference Notice: This printout from THE INDIAN PHARMACIST (https://theindianpharmacist.com/medicine/11-19-paroxetine-hydrochloride-controlled-release-ssri/, Last Reviewed: 2026-11-10) is an educational reference sheet for students and healthcare learners. It is NOT an official prescribing guideline or patient-specific treatment order.