1. Clinical & Scientific Overview
Irinotecan Hydrochloride (TIP-MED-000565, Reference Code [ONC-16]) is classified under
Oncology & Antineoplastic Medicines as a Topoisomerase I Inhibitor (S-Phase Specific) • Water-Soluble Camptothecin Analogue Topoisomerase I Inhibitor.
Within the Indian regulatory and compendial framework, it is governed under Schedule H (Prescription Only — Specialist Oncology Supervision).
Camptosar (Pfizer Ltd), Irinotel (Fresenius Kabi Oncology), Irinocam (Dr. Reddy's Laboratories)
Concentrate for IV Infusion: 40 mg/2 mL, 100 mg/5 mL vials
Oncology Specialisation & Cytotoxic Safety Protocol
Topoisomerase I Inhibitor (S-Phase Specific)
Antineoplastic Cytotoxic
Standard Regimen & Cycle Context: FOLFIRI: 180 mg/m2 IV over 90 minutes every 14 days (reduce starting dose by 30% in UGT1A1*28/*28 homozygotes).
Signature Dose-Limiting Toxicities & Organ Monitoring: BIPHASIC DIARRHOEA SYNDROME: (1) Early-Onset (<24 hours): Cholinergic surge (abdominal cramping, explosive diarrhoea, diaphoresis, hypersalivation, lacrimation, bradycardia) due to acetylcholinesterase inhibition — treated/prevented immediately with Atropine 0.25–1 mg SC/IV; (2) Late-Onset (>24 hours, median Day 5): Direct SN-38 mucosal toxicity (life-threatening dehydration + neutropenic sepsis) — treated aggressively with high-dose Loperamide (4 mg initially, then 2 mg every 2 hours until 12 hours diarrhoea-free).
Extravasation, Premedication & Safe Cytotoxic Handling: Screen for Gilbert syndrome / UGT1A1*28 polymorphism; dispense an emergency pack of Loperamide 2 mg capsules with written instructions to start at the very first liquid stool appearing >24 hours post-infusion.
3. Mechanism of Action & Pharmacodynamics
Prodrug converted by hepatic and gastrointestinal carboxylesterases to SN-38 (100–1,000x more potent), which stabilizes the Topoisomerase I-DNA cleavable complex; SN-38 is inactivated by hepatic UGT1A1 glucuronidation to SN-38G.
4. Therapeutic Indications & Evidence-Supported Uses
- Metastatic Colorectal Carcinoma (FOLFIRI and FOLFIRINOX regimens)
- Pancreatic and Gastro-oesophageal Adenocarcinoma
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: Educational Oncology Regimen Context (Specialist Reference Only): FOLFIRI: 180 mg/m2 IV over 90 minutes every 14 days (reduce starting dose by 30% in UGT1A1*28/*28 homozygotes).
Administration & Meal Timing: FOLFIRI: 180 mg/m2 IV over 90 minutes every 14 days (reduce starting dose by 30% in UGT1A1*28/*28 homozygotes).
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Specialist oncology pharmacokinetic profile; dosing depends on Body Surface Area (BSA in m2), Calvert GFR formula, or flat targeted dosing with strict organ-function adjustments.
Hepatic enzymatic activation/inactivation or proteolytic degradation (for monoclonal antibodies); see specific polymorphism and interaction notes.
Verify serum creatinine and eGFR before every cycle; see drug-specific renal dosing and uroprotection rules.
Check total bilirubin, AST, and ALT prior to each cycle; taxanes, anthracyclines, and TKIs require strict hepatic dose modification.
7. Contraindications, Precautions & High-Risk Warnings
- Severe hypersensitivity to Irinotecan or formulation vehicle
- Pregnancy and lactation (potent teratogen/embryotoxic class warning unless explicitly evaluated by oncology specialist)
- Severe unrecovered bone marrow aplasia or decompensated organ failure per protocol thresholds
Key Clinical Precautions: BIPHASIC DIARRHOEA SYNDROME: (1) Early-Onset (<24 hours): Cholinergic surge (abdominal cramping, explosive diarrhoea, diaphoresis, hypersalivation, lacrimation, bradycardia) due to acetylcholinesterase inhibition — treated/prevented immediately with Atropine 0.25–1 mg SC/IV; (2) Late-Onset (>24 hours, median Day 5): Direct SN-38 mucosal toxicity (life-threatening dehydration + neutropenic sepsis) — treated aggressively with high-dose Loperamide (4 mg initially, then 2 mg every 2 hours until 12 hours diarrhoea-free).
8. Adverse Effects Profile
- BIPHASIC DIARRHOEA SYNDROME: (1) Early-Onset (<24 hours): Cholinergic surge (abdominal cramping, explosive diarrhoea, diaphoresis, hypersalivation, lacrimation, bradycardia) due to acetylcholinesterase inhibition — treated/prevented immediately with Atropine 0.25–1 mg SC/IV; (2) Late-Onset (>24 hours, median Day 5): Direct SN-38 mucosal toxicity (life-threatening dehydration + neutropenic sepsis) — treated aggressively with high-dose Loperamide (4 mg initially, then 2 mg every 2 hours until 12 hours diarrhoea-free).
- BIPHASIC DIARRHOEA SYNDROME: (1) Early-Onset (<24 hours): Cholinergic surge (abdominal cramping, explosive diarrhoea, diaphoresis, hypersalivation, lacrimation, bradycardia) due to acetylcholinesterase inhibition — treated/prevented immediately with Atropine 0.25–1 mg SC/IV; (2) Late-Onset (>24 hours, median Day 5): Direct SN-38 mucosal toxicity (life-threatening dehydration + neutropenic sepsis) — treated aggressively with high-dose Loperamide (4 mg initially, then 2 mg every 2 hours until 12 hours diarrhoea-free).
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- BIPHASIC DIARRHOEA SYNDROME: (1) Early-Onset (<24 hours): Cholinergic surge (abdominal cramping, explosive diarrhoea, diaphoresis, hypersalivation, lacrimation, bradycardia) due to acetylcholinesterase inhibition — treated/prevented immediately with Atropine 0.25–1 mg SC/IV; (2) Late-Onset (>24 hours, median Day 5): Direct SN-38 mucosal toxicity (life-threatening dehydration + neutropenic sepsis) — treated aggressively with high-dose Loperamide (4 mg initially, then 2 mg every 2 hours until 12 hours diarrhoea-free).
- Avoid live-attenuated vaccines during immunosuppressive chemotherapy; verify CYP3A4, UGT1A1, DPD, and QTc interactions before each cycle.
10. Clinical Monitoring, Patient Counselling & Storage
Clinical & Laboratory Monitoring: Screen for Gilbert syndrome / UGT1A1*28 polymorphism; dispense an emergency pack of Loperamide 2 mg capsules with written instructions to start at the very first liquid stool appearing >24 hours post-infusion.
Pharmacist Patient Counselling Points:
- Screen for Gilbert syndrome / UGT1A1*28 polymorphism; dispense an emergency pack of Loperamide 2 mg capsules with written instructions to start at the very first liquid stool appearing >24 hours post-infusion.
- Report fever >=38.0°C (100.4°F) immediately (medical emergency: possible febrile neutropenia).
- Follow strict reproductive contraception and safe cytotoxic oral handling instructions.
Storage, Stability & Dispensing Safeguards: Screen for Gilbert syndrome / UGT1A1*28 polymorphism; dispense an emergency pack of Loperamide 2 mg capsules with written instructions to start at the very first liquid stool appearing >24 hours post-infusion.
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
12. Authoritative References, Regulatory Sources & Editorial Disclaimer
Primary Compendial & Guideline Reference: National Cancer Grid (NCG) India Consensus Guidelines; NLEM 2022 Antineoplastic Section; Indian Pharmacopoeia (IP) & CDSCO Approved Oncology Prescribing Information.
Official Verification Portals: National Cancer Grid (NCG) India — Evidence-Based Oncology Guidelines • CDSCO — Central Drugs Standard Control Organization Approved Drug Data • Indian Pharmacopoeia Commission (IPC)
Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_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.