Campto Irinotecan Hydrochloride Injection

1. Indications and Usage
Metastatic Colorectal Cancer: Treatment of metastatic colorectal cancer as a single agent in patients who have failed fluoropyrimidine-, anthracycline-, and oxaliplatin-based regimens, or in combination with fluoropyrimidine and leucovorin in first-line therapy.
2. Dosage and Administration
Standard Regimen: The recommended dose is 350 mg/m² administered intravenously over 90 minutes once every 4 weeks, or 180 mg/m² over 30 to 90 minutes once weekly for 5 consecutive weeks in every 6-week cycle.
Dose Adjustments: Dosage must be reduced based on the occurrence of severe or recurrent neutropenia, thrombocytopenia, or severe diarrhea.
Administration: Do not administer as an intravenous push or bolus.
Special Populations: Dosage reduction is mandatory for patients with bilirubin exceeding 1.5 times the upper limit of normal.
3. Mechanism of Action
Topoisomerase I Inhibition: Irinotecan acts as a potent inhibitor of topoisomerase I, an enzyme responsible for resolving DNA topological problems associated with transcription and replication.
DNA Damage: It stabilizes the reversible complex between topoisomerase I and DNA, leading to double-strand DNA breaks during replication and subsequent cell death.
Active Metabolite: It is a prodrug that is converted in vivo to its active metabolite, SN-38, which has significantly greater inhibitory activity than the parent compound.
4. Safety and Warnings
Severe Neutropenia: The most common dose-limiting toxicity is severe neutropenia; fever and infection must be monitored closely.
Severe Diarrhea: Both early-onset and late-onset diarrhea are common and can be life-threatening due to dehydration and electrolyte imbalance.
Acute Cholinergic Syndrome: Characterized by early-onset diarrhea, abdominal cramping, rhinorrhea, and sweating during or shortly after infusion.
Tumor Lysis Syndrome: May occur rapidly following the first dose, especially in patients with a high tumor burden.
5. Adverse Reactions and Clinical Research
Common: Neutropenia, severe diarrhea, nausea, vomiting, alopecia, and fatigue.
Serious: Febrile neutropenia, sepsis, perforation of the colon, and severe dehydration.
Clinical Research: Clinical trials have demonstrated significant improvement in response rates and progression-free survival when used in combination regimens for colorectal cancer.
6. Drug Interactions
CYP3A4 Inhibitors: Strong inhibitors (e.g., ketoconazole, itraconazole) increase SN-38 exposure and toxicity; caution is required.
CYP3A4 Inducers: Strong inducers (e.g., phenytoin, carbamazepine, rifampin) decrease SN-38 exposure and therapeutic effect.
Neuromuscular Blockers: Irinotecan may prolong neuromuscular blockade, increasing the risk of prolonged respiratory depression.
Live Vaccines: Concomitant use is contraindicated due to the risk of vaccine infection.
7. Pharmaceutical Information
Active Ingredient: Irinotecan Hydrochloride.
Appearance: Clear, colorless to pale yellow liquid solution.
Storage: Store at 25°C; protect from light. Do not freeze.