Irinotecan Glenmark (Irinotecan Hydrochloride Trihydrate)

• Irinotecan is indicated for colorectal cancer treatment, targeting tumor growth and progression.
• Metastatic colorectal cancer: improves overall survival when used in combination chemotherapy regimens.
• Advanced colorectal cancer: provides disease control in patients with unresectable disease.
• Colorectal cancer (first‑line therapy): used with fluoropyrimidines to enhance response rates.

• Irinotecan is a prodrug 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 during replication, resulting in accumulation of DNA damage and ultimately tumor cell death.

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

Common Side Effects

• Nausea and vomiting: gastrointestinal upset commonly observed during infusion.
• Diarrhea: may be mild to moderate and often requires supportive care.
• Neutropenia: reduction in white blood cells increasing infection risk.
• Fatigue: generalized tiredness during treatment cycles.

Serious or Rare Side Effects

• Severe neutropenia or febrile neutropenia: can lead to life‑threatening infections.
• Acute severe diarrhea (colitis): may require hospitalization and intensive management.
• Allergic reactions: including rash, pruritus, or anaphylaxis.
• Hepatic or pulmonary toxicity: rare organ‑specific adverse events.

• Before initiating Irinotecan therapy, clinicians should consider several safety measures to minimize risk.
• Blood count monitoring: perform complete blood counts before each cycle to detect neutropenia.
• Liver function assessment: evaluate hepatic enzymes as Irinotecan is metabolized hepatically.
• Bowel obstruction evaluation: assess for pre‑existing gastrointestinal blockage.
• Renal impairment dose adjustment: modify dosing in patients with reduced kidney function.
• Store at ambient temperature: keep in original packaging, protect from moisture and light.

Irinotecan can interact with other medicines, affecting its efficacy or toxicity.

Major Interactions (Avoid)

• Strong UGT1A1 inhibitors (e.g., atazanavir): may increase toxic metabolite levels, leading to severe neutropenia.
• Potent CYP3A4 inhibitors (e.g., ketoconazole): raise plasma concentrations and risk of toxicity.
• Live bacterial vaccines: risk of infection due to immunosuppression.

Moderate Interactions (Monitor Closely)

• Moderate CYP3A4 inhibitors (e.g., erythromycin): may modestly increase exposure.
• Enzyme inducers (e.g., rifampicin): can lower drug levels, reducing efficacy.
• Other myelosuppressive agents (e.g., carboplatin): may enhance bone‑marrow suppression.