Irinotecan Hydrochloride Accord Healthcare Ireland (Irinotecan Hydrochloride Trihydrate)

Irinotecan Hydrochloride is used in the management of colorectal cancer and related disease pathways.

• Colorectal cancer: improves survival by targeting rapidly dividing tumor cells.
• Metastatic colorectal cancer: provides systemic therapy for advanced disease.
• Advanced colorectal carcinoma: used as part of combination chemotherapy regimens to reduce tumor burden.

• Irinotecan Hydrochloride binds to the DNA‑topoisomerase I complex and stabilizes it, preventing the re‑ligation step of DNA replication. This leads to accumulation of single‑strand DNA breaks, which are converted into double‑strand breaks during replication, ultimately causing tumor cell apoptosis.

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

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Diarrhea: often severe and may require antidiarrheal therapy.
• Fatigue: general tiredness during treatment cycles.
• Alopecia: hair loss that is usually reversible.
• Neutropenia: reduced neutrophil count increasing infection risk.
• Anemia: lowered red blood cell count causing fatigue.

Serious or Rare Side Effects

• Severe neutropenia: profound drop in neutrophils requiring medical intervention.
• Febrile neutropenia: fever with low neutrophils, a medical emergency.
• Severe diarrhea (colitis): can lead to dehydration and electrolyte imbalance.
• Liver enzyme elevation: indicates hepatic stress.
• Allergic reactions: rash, itching, or anaphylaxis.
• Pulmonary toxicity: rare lung inflammation.

When using Irinotecan Hydrochloride, clinicians should observe several precautionary measures to ensure patient safety.

• Assess baseline blood counts: obtain a complete blood count before each cycle.
• Monitor liver function: check hepatic enzymes regularly.
• Adjust dose in hepatic impairment: reduce dosage according to liver function tests.
• Avoid concurrent strong CYP3A4 inhibitors: these may increase exposure.
• Educate patients on early signs of diarrhea: prompt antidiarrheal therapy is essential.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan Hydrochloride interacts with several drugs that can alter its efficacy or toxicity.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase toxicity.
• Concurrent use of other topoisomerase I inhibitors: additive bone marrow suppression.
• High-dose aspirin or NSAIDs: increased risk of gastrointestinal toxicity.

Moderate Interactions (Monitor Closely)

• UGT1A1 inhibitors (e.g., atazanavir): may raise plasma levels.
• Anticoagulants (e.g., warfarin): monitor INR for bleeding risk.
• Radiotherapy to abdomen: may enhance gastrointestinal toxicity.