Irinotecan Hydrochloride Qilu Pharma Spain (Irinotecan Hydrochloride Trihydrate)

• Irinotecan is a topoisomerase I inhibitor used within colorectal cancer treatment pathways.
• Metastatic colorectal cancer: improves overall survival when combined with fluoropyrimidine‑based chemotherapy.
• Adjuvant treatment of colon cancer: reduces risk of disease recurrence after surgical resection.
• Stage III colon cancer (post‑surgery): used as part of adjuvant therapy to enhance disease‑free survival.

• Irinotecan is a pro‑drug that is converted intracellularly to SN‑38, a potent inhibitor of topoisomerase I. By stabilizing the transient DNA‑topoisomerase I complex, SN‑38 prevents relegation of single‑strand DNA breaks, leading to accumulation of DNA damage during replication. This interruption of DNA synthesis triggers apoptosis preferentially in rapidly dividing tumor cells, providing antitumor activity in colorectal malignancies.

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

Common Side Effects

• Nausea: mild to moderate nausea often occurring during or shortly after infusion.
• Diarrhea: frequent watery stools that may require antidiarrheal therapy.
• Neutropenia: reduced neutrophil count increasing infection risk, typically monitored with CBC.
• Fatigue: generalized tiredness that can affect daily activities.

Serious or Rare Side Effects

• Febrile neutropenia: severe neutropenia accompanied by fever, requiring urgent medical attention.
• Grade 3‑4 diarrhea or colitis: intense intestinal inflammation that may lead to dehydration.
• Hepatic dysfunction: marked elevation of bilirubin or transaminases indicating liver injury.
• Hypersensitivity reactions: rash, bronchospasm, or anaphylaxis occurring during infusion.

When using Irinotecan, clinicians should observe several precautionary measures to minimize toxicity.

• Monitor blood counts: perform regular complete blood count tests to detect neutropenia early.
• Assess liver function: evaluate hepatic enzymes before treatment and periodically during therapy.
• Check renal function: adjust dosing or schedule if significant renal impairment is present.
• Avoid concurrent myelosuppressive agents: reduce risk of severe bone‑marrow suppression by limiting overlapping toxic drugs.
• Pregnancy considerations: use only if potential benefit justifies potential risk, as data are limited.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan can interact with other medicines, influencing its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin): may markedly lower Irinotecan exposure and reduce therapeutic effect.
• UGT1A1 inhibitors (e.g., atazanavir): can increase SN‑38 levels, raising risk of severe toxicity.
• Concurrent myelosuppressive chemotherapy: may amplify bone‑marrow suppression and infection risk.
• Live vaccines: immunosuppression may increase susceptibility to vaccine‑derived infections.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): monitor INR closely for enhanced bleeding tendency.
• Diuretics: watch electrolyte balance as dehydration can worsen renal clearance.
• Anticholinergic agents: may exacerbate constipation associated with Irinotecan.