Irinotecan Accord (Irinotecan Hydrochloride Trihydrate)

Irinotecan Accord is a topoisomerase I inhibitor used in the management of colorectal cancer, particularly in advanced disease stages where systemic therapy is required.

• Metastatic colorectal cancer: used as part of combination chemotherapy regimens to improve survival in adult patients with advanced disease.
• Colorectal cancer (first‑line): combined with fluoropyrimidines and oxaliplatin as a first‑line option for patients with unresectable disease.

• Irinotecan is a semisynthetic derivative of the natural alkaloid camptothecin. After intravenous administration it is converted to its active metabolite SN‑38, which binds to the DNA‑topoisomerase I complex. This binding stabilizes the transient single‑strand breaks introduced during DNA replication, preventing relegation and leading to accumulation of DNA damage, replication arrest and ultimately tumor cell death. The effect is selective for rapidly proliferating cells, making it effective against malignant tumors.

Irinotecan Accord may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Neutropenia: reduced white blood cell count increasing infection risk.
• Diarrhea: often severe and may require antidiarrheal therapy.
• Nausea and vomiting: typical chemotherapy‑related symptoms.
• Fatigue: generalized tiredness affecting daily activities.
• Alopecia: temporary hair loss during treatment.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophils requiring urgent care.
• Severe colitis: life‑threatening inflammation of the colon.
• Hepatic toxicity: elevated liver enzymes or bilirubin.
• Hypersensitivity reactions: rash, bronchospasm, or anaphylaxis.
• Tumor lysis syndrome: rapid tumor cell breakdown causing metabolic disturbances.

Prior to initiating therapy, clinicians should evaluate patient suitability and monitor for potential complications.

• Blood count monitoring: perform regular CBC to detect neutropenia early.
• Liver function assessment: check hepatic enzymes and bilirubin before each cycle.
• Dose adjustment: modify dosing in patients with hepatic impairment.
• Concomitant myelosuppressives: avoid or use with caution when combined with other bone‑marrow‑suppressing agents.
• Pregnancy and lactation: safety not established; avoid use in pregnant or nursing women.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan may interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole): increase SN‑38 exposure and toxicity.
• UGT1A1 inhibitors (e.g., atazanavir): raise active metabolite levels, heightening risk of neutropenia and diarrhea.
• Concurrent myelosuppressive agents: additive bone‑marrow suppression may become severe.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin): reduce drug exposure, potentially lowering effectiveness.
• Anticoagulants (e.g., warfarin): may require INR monitoring due to altered metabolism.
• Other chemotherapeutic agents: overlapping toxicities such as mucositis or hepatic strain should be observed.