Irinotecan Kabi (Irinotecan Hydrochloride Trihydrate)

Irinotecan is employed in oncology for cancers that are treated with topoisomerase I‑targeted chemotherapy.

• Metastatic colorectal cancer: used in combination regimens to improve progression‑free and overall survival.
• Other solid tumours: incorporated into multi‑agent chemotherapy protocols for disease control.
• Advanced colorectal cancer after first‑line failure: administered to achieve tumour response in later‑line therapy.

• Irinotecan is a pro‑drug that is converted intracellularly to SN‑38, a potent inhibitor of topoisomerase I. By stabilising the transient DNA‑topoisomerase I complex, it prevents religation of single‑strand DNA breaks, leading to accumulation of DNA damage, replication arrest and ultimately apoptotic cell death in rapidly dividing tumour cells.

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

Common Side Effects

• Diarrhoea: often delayed and may be severe.
• Neutropenia: reduced white blood cell count increasing infection risk.
• Nausea and vomiting: typical chemotherapy‑related symptoms.
• Fatigue: generalized tiredness during treatment cycles.
• Alopecia: hair loss that may be temporary.
• Abdominal pain: discomfort in the gastrointestinal tract.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophil count requiring urgent care.
• Severe diarrhoea (colitis): can lead to dehydration and electrolyte imbalance.
• Hepatic toxicity: elevated liver enzymes or jaundice.
• Allergic reactions: rash, bronchospasm or anaphylaxis.
• Secondary malignancies: rare risk of therapy‑related cancers.
• Severe mucositis: painful inflammation of the mouth and gastrointestinal lining.

Prior to initiating Irinotecan therapy, several safety considerations should be addressed.

• Monitor blood counts: perform regular complete blood counts to detect neutropenia.
• Assess liver function: evaluate hepatic enzymes and bilirubin before each cycle.
• Evaluate bowel status: avoid use in patients with recent bowel obstruction or perforation.
• Dose adjustment: consider reduced dosing in patients with hepatic impairment.
• Hypersensitivity: discontinue if signs of an allergic reaction appear.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan interacts with several drugs that may alter its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce SN‑38 exposure.
• UGT1A1 inhibitors (e.g., atazanavir, indinavir): can increase SN‑38 levels and toxicity.
• Concurrent myelosuppressive agents: heighten risk of severe neutropenia.

Moderate Interactions (Monitor Closely)

• Antiemetics such as ondansetron: may affect SN‑38 metabolism.
• Anticoagulants (e.g., warfarin): increased bleeding risk.
• NSAIDs: may exacerbate gastrointestinal toxicity.
• Proton pump inhibitors: potential impact on drug absorption and metabolism.