Irinotecanhydrochlorid 3 H2o Vitane (Irinotecan Hydrochloride Trihydrate)

Irinotecan Hydrochloride is indicated for colorectal cancer therapies that target the topoisomerase I pathway.

• Metastatic colorectal cancer (first‑line): used with fluorouracil and leucovorin to improve response rates and overall survival.
• Metastatic colorectal cancer (second‑line): employed after disease progression on prior chemotherapy to provide additional disease control.
• Colorectal cancer (adjuvant setting): administered as part of postoperative chemotherapy to reduce recurrence risk.

• Irinotecan is a prodrug 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 during replication, leading to accumulation of DNA damage, replication arrest, and ultimately tumor cell apoptosis. The effect is selective for rapidly dividing cancer cells.

Irinotecan may cause a range of adverse reactions, varying in frequency and severity.

Common Side Effects

• Neutropenia: reduced white blood cell count increasing infection risk.
• Diarrhea: often severe and may require intensive management.
• Nausea: frequent during and after infusion.
• Vomiting: may accompany nausea.
• Alopecia: hair loss observed in many patients.
• Fatigue: general tiredness and weakness.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophils, a medical emergency.
• Colitis/ileitis: severe inflammation of the colon or ileum.
• Hepatic dysfunction: elevated liver enzymes or jaundice.
• Allergic reactions: rash, bronchospasm, or anaphylaxis.
• Pulmonary toxicity: interstitial lung disease or pneumonitis.
• Severe electrolyte disturbances: hypokalemia or hyponatremia.

Prior to initiating therapy, several safety measures should be observed.

• Monitor blood counts: perform complete blood count before each cycle to detect neutropenia.
• Assess liver function: evaluate hepatic enzymes and bilirubin prior to dosing and during therapy.
• Evaluate gastrointestinal status: screen for bowel obstruction or inflammatory bowel disease before treatment.
• Adjust dose in hepatic impairment: reduce dose according to bilirubin levels and liver function tests.
• Avoid in patients with known hypersensitivity: discontinue if severe allergic reaction occurs.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze.

Irinotecan may interact with other medicines, influencing its safety or effectiveness.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase SN‑38 exposure, heightening toxicity.
• UGT1A1 inhibitors (e.g., atazanavir): reduce SN‑38 clearance, raising risk of neutropenia and diarrhea.
• Concurrent myelosuppressive chemotherapy: additive bone‑marrow suppression may be life‑threatening.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): lower SN‑38 levels, potentially reducing efficacy.
• Antidiarrheal agents (e.g., loperamide) used for symptom control: may mask severity of irinotecan‑induced diarrhea.
• Anticoagulants (e.g., warfarin): monitor coagulation parameters as irinotecan can affect platelet counts.