Irinotecan Ever Pharma (Irinotecan Hydrochloride Trihydrate)

Irinotecan is used in oncology to target cancers that respond to topoisomerase I inhibition.

• Metastatic colorectal cancer: improves overall survival when combined with fluorouracil and leucovorin.
• Adjuvant colorectal cancer: reduces risk of disease recurrence after surgical resection.
• Advanced colorectal cancer (refractory): provides disease control in patients who have progressed on prior therapies.

• Irinotecan is a pro‑drug that is converted intracellularly to SN‑38, a potent inhibitor of topoisomerase I. By stabilizing the DNA‑topoisomerase I complex, it prevents relegation of single‑strand DNA breaks, leading to accumulation of DNA damage and ultimately triggering apoptosis in rapidly dividing tumor cells.

Irinotecan may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Diarrhea: often severe and may require antidiarrheal therapy.
• Neutropenia: reduced white blood cell count increasing infection risk.
• Nausea and vomiting: may be managed with antiemetics.
• Alopecia: temporary hair loss.
• Fatigue: general tiredness during treatment.
• Abdominal cramping: discomfort in the stomach area.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophil count requiring urgent care.
• Severe colitis: inflammation of the colon that can be life‑threatening.
• Hepatotoxicity: liver enzyme elevations indicating liver injury.
• Hypersensitivity reactions: rash, bronchospasm, or anaphylaxis.
• Hemorrhagic cystitis: bladder inflammation with bleeding.
• Cardiotoxicity: rare heart rhythm disturbances.

Before initiating therapy, clinicians should assess patient-specific risk factors and monitor laboratory parameters closely.

• Baseline blood counts: obtain CBC to detect pre‑existing neutropenia.
• Liver function: evaluate hepatic enzymes as irinotecan is metabolized hepatically.
• Renal function: adjust dosing in patients with impaired clearance.
• Concomitant medications: avoid drugs that strongly inhibit UGT1A1, which may increase SN‑38 exposure.
• Pregnancy and lactation: contraindicated unless benefits outweigh risks; discuss with obstetric specialist.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan interacts with several agents that can alter its metabolism or increase toxicity.

Major Interactions (Avoid)

• Strong UGT1A1 inhibitors (e.g., atazanavir): may raise SN‑38 levels and risk severe neutropenia.
• CYP3A4 inducers (e.g., rifampin): can reduce efficacy by increasing drug clearance.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): monitor INR as irinotecan may affect clotting parameters.
• Other myelosuppressive agents: increase risk of profound bone‑marrow suppression.
• Antidiarrheal agents (e.g., loperamide): use cautiously to avoid masking severe diarrhea.
• Proton pump inhibitors: may affect gastric pH and drug absorption modestly.