1. Clinical & Scientific Overview
Fluoxetine Hydrochloride (TIP-MED-000207, Reference Code [11.3]) is classified under
CNS & Psychiatric Medicines (Ch 11) as a Selective Serotonin Reuptake Inhibitor (Activating Long-Half-Life SSRI).
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).
Representative Indian Market Examples (Edition 2.7 Ch 11 [11.3], p. 141): Fludac (Cadila), Prozac (Lilly), Flunil (Intas), Prodep (Sun Pharma) — Strengths & Dosage Forms: Oral Capsules / Dispersible Tablets: 10 mg, 20 mg, 40 mg, 60 mg
Oral Capsules / Dispersible Tablets: 10 mg, 20 mg, 40 mg, 60 mg
3. Mechanism of Action & Pharmacodynamics
Selective Serotonin Reuptake Inhibitor (Activating Long-Half-Life SSRI) acting on target receptor/enzyme pathways in CNS & Psychiatric Medicines (Ch 11): clinical efficacy is mediated via Selective Serotonin Reuptake Inhibitor (Activating Long-Half-Life SSRI) for Major depressive disorder (particularly depression characterised by psychomotor retardation, hypersomnia, and apathy); obsessive-compulsive disorder (OCD—40 to 60 mg/day); bulimia nervosa (60 mg/day); panic disorder..
4. Therapeutic Indications & Evidence-Supported Uses
- Major depressive disorder (particularly depression characterised by psychomotor retardation, hypersomnia, and apathy)
- obsessive-compulsive disorder (OCD—40 to 60 mg/day)
- bulimia nervosa (60 mg/day)
- panic disorder
🇮🇳 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: General Adult Reference: Depression: Initially 20 mg once daily in the morning (in elderly: initiate at 10 mg once daily); may increase after 3–4 weeks to 40–60 mg/day. Follow psychiatrist prescription.
Administration & Meal Timing: With or without food (usually taken with or after breakfast). | Strictly in the MORNING (with breakfast)! Fluoxetine is the most activating/energising SSRI—taking it in the evening or at bedtime causes severe insomnia and nocturnal agitation!
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Renal: No adjustment needed in mild-to-moderate CKD. Hepatic: In cirrhosis, Norfluoxetine half-life extends beyond 2–3 weeks! Reduce dose by 50% or administer on alternate days.
Renal: No adjustment needed in mild-to-moderate CKD. Hepatic: In cirrhosis, Norfluoxetine half-life extends beyond 2–3 weeks! Reduce dose by 50% or administer on alternate days.
Renal: No adjustment needed in mild-to-moderate CKD. Hepatic: In cirrhosis, Norfluoxetine half-life extends beyond 2–3 weeks! Reduce dose by 50% or administer on alternate days.
7. Contraindications, Precautions & High-Risk Warnings
- Contraindicated with MAOIs (must wait ≥5 weeks after stopping fluoxetine before starting an MAOI!), pimozide, and thioridazine. Caution in epilepsy, bipolar mania, diabetes (can cause hypoglycaemia during therapy and hyperglycaemia upon withdrawal), and bleeding disorders.
Key Clinical Precautions: Renal: No adjustment needed in mild-to-moderate CKD. Hepatic: In cirrhosis, Norfluoxetine half-life extends beyond 2–3 weeks! Reduce dose by 50% or administer on alternate days.
8. Adverse Effects Profile
- Insomnia, nervousness, anxiety/restlessness (especially in first 2 weeks), anorexia and mild weight loss initially, nausea, diarrhoea, headache, fine tremor, sexual dysfunction.
- SIADH Hyponatraemia in the elderly, Upper GI Bleeding (with NSAIDs/antiplatelets), Serotonin Syndrome, manic switch in bipolar patients, QTc prolongation (at high doses).
- Monitor for severe hypersensitivity, organ toxicity, or dose-limiting adverse events.
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- POTENT, LONG-LASTING INHIBITOR OF CYP2D6 AND MODERATE INHIBITOR OF CYP2C19 / CYP2C9 / CYP3A4! (Interactions persist for 5 weeks after stopping fluoxetine!): • Beta-Blockers (Metoprolol, Carvedilol, Propranolol, Nebivolol): Fluoxetine blocks CYP2D6, increasing Metoprolol plasma levels 3- to 5-fold and precipitating severe bradycardia and heart block! • Tamoxifen (in Breast Cancer): Fluoxetine blocks CYP2D6 conversion of Tamoxifen to active Endoxifen—causing breast cancer relapse! Never give Fluoxetine or Paroxetine to a patient on Tamoxifen (use Venlafaxine or Escitalopram/Sertraline cautiously instead)! • Tramadol & Codeine: Blocks CYP2D6 analgesic activation while triggering Serotonin Syndrome! • Tricyclic Antidepressants (Amitriptyline, Nortriptyline), Haloperidol, Risperidone, Phenytoin, Carbamazepine, and Warfarin: Markedly increases plasma levels and toxicity!
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: Always take Fludac/Prodep in the morning after breakfast so it does not keep you awake at night. Inform any doctor prescribing heart, pain, epilepsy, or breast cancer medicines that you take Fluoxetine, even if you stopped taking it a month ago!
- Meal & Clock Timing Instruction: With or without food (usually taken with or after breakfast). (Strictly in the MORNING (with breakfast)! Fluoxetine is the most activating/energising SSRI—taking it in the evening or at bedtime causes severe insomnia and nocturnal agitation!)
- Missed Dose Protocol: Because of its 4-to-15 day half-life, missing a single daily capsule has virtually zero impact on blood levels—simply resume the normal morning capsule the next day; never double.
- Geriatric Dispensing Pearl: Because of its extremely long 15-day norfluoxetine half-life in the elderly, potent CYP2D6 inhibition (causing metoprolol bradycardia and TCA toxicity), and activating insomnia, Sertraline or low-dose Escitalopram is strongly preferred over Fluoxetine in elderly polypharmacy patients.
Storage, Stability & Dispensing Safeguards: Store below 25°C–30°C in original moisture- and light-resistant packaging out of reach of children. Available forms: Oral Capsules / Dispersible Tablets: 10 mg, 20 mg, 40 mg, 60 mg
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
12. Authoritative References, Regulatory Sources & Editorial Disclaimer
Primary Compendial & Guideline Reference: Indian Pharmacist Desk Reference — Professional Edition 2.7 (2026–27) • Ch 11 [11.3] (p. 141)
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.
13. Related Reference Monographs, Educational Guides & Visual Concept
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