Irinotecano Azevedos (Irinotecan Hydrochloride)

Irinotecan is used in colorectal cancer regimens that target tumor cell proliferation.

• Metastatic colorectal cancer: used in combination chemotherapy to improve overall survival and disease control.
• Advanced colorectal cancer: administered as part of second‑line therapy to achieve tumor response.
• Colorectal cancer (first‑line with FOLFIRI): combined with fluorouracil and leucovorin to enhance treatment efficacy.

• Irinotecan is a pro‑drug that is converted intracellularly to SN‑38, a potent inhibitor of topoisomerase I. By stabilizing the enzyme‑DNA cleavable complex, it prevents relegation of single‑strand DNA breaks during replication, leading to accumulation of DNA damage and apoptosis of rapidly dividing tumor cells. The active metabolite binds to the DNA‑topoisomerase I complex, interfering with the religation step and causing double‑strand breaks during S‑phase, which triggers cell‑cycle arrest and programmed cell death.

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

Common Side Effects

• Diarrhea: often severe and may require antidiarrheal therapy.
• Neutropenia: reduced white blood cell count increasing infection risk.
• Nausea: feeling of sickness often accompanied by vomiting.
• Fatigue: persistent tiredness affecting daily activities.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophils requiring urgent medical care.
• Severe colitis: intense inflammation of the colon leading to abdominal pain and blood in stool.
• Allergic reaction: rash, itching, swelling, or anaphylaxis.
• Hepatic toxicity: elevated liver enzymes or jaundice indicating liver injury.

Before using Irinotecano Azevedos, several safety considerations should be observed.

• Renal impairment: monitor kidney function and adjust therapy as needed.
• Hepatic impairment: assess liver enzymes and consider dose modification.
• Pregnancy: avoid use unless benefits outweigh potential fetal risks.
• Concomitant radiation therapy: increased risk of gastrointestinal toxicity.
• Monitor blood counts: regular CBC testing to detect neutropenia early.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan interacts with several medicines that can alter its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase irinotecan exposure and toxicity.
• UGT1A1 inhibitors (e.g., atazanavir): raise SN‑38 levels, heightening risk of neutropenia and diarrhea.
• Concurrent myelosuppressive agents (e.g., carboplatin, paclitaxel): additive bone‑marrow suppression.

Moderate Interactions (Monitor Closely)

• Antiemetics such as ondansetron: may affect metabolism of irinotecan.
• Warfarin: monitor INR as irinotecan can influence anticoagulant effect.
• Fluoroquinolones (e.g., ciprofloxacin): potential increase in gastrointestinal side effects.