Irinomedac (Irinotecan Hydrochloride Trihydrate)

• Irinotecan is employed in oncology regimens targeting specific solid tumours.
• Metastatic colorectal cancer: improves overall survival when combined with fluoropyrimidine‑based chemotherapy.
• Adjuvant treatment of colon cancer: reduces the risk of disease recurrence after surgical resection.
• Small cell lung cancer (off‑label): may be incorporated into combination chemotherapy protocols for disease control.

• After intravenous administration, irinotecan is converted by hepatic carboxylesterases to the active metabolite SN‑38. SN‑38 binds to the DNA‑topoisomerase I complex, preventing relegation of single‑strand DNA breaks during replication. This stabilisation leads to accumulation of DNA damage, triggering apoptosis in rapidly dividing cancer cells.

Irinotecan is associated with a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Neutropenia: reduced white blood cell count increasing infection risk.
• Diarrhea: often severe and may require supportive care.
• Nausea and vomiting: typical chemotherapy‑related symptoms.
• Alopecia: temporary hair loss.
• Fatigue: generalized tiredness during treatment.
• Anemia: decreased red blood cell levels.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophils requiring urgent medical attention.
• Severe colitis or intestinal perforation.
• Hepatotoxicity: elevated liver enzymes or liver dysfunction.
• Allergic reactions: rash, bronchospasm, or anaphylaxis.
• Hand‑foot syndrome: painful redness and swelling of palms and soles.
• Cardiotoxicity: rare cardiac rhythm disturbances.

• Prior to initiating therapy, clinicians should assess patient‑specific risk factors and monitor relevant parameters.
• Monitor blood counts: perform regular complete blood counts to detect neutropenia.
• Assess liver function: evaluate hepatic enzymes before and during treatment.
• Screen for bowel obstruction: consider baseline imaging in patients with prior abdominal surgery.
• Adjust dose in hepatic impairment: reduce dosage according to liver function test results.
• Avoid in known hypersensitivity: discontinue if severe allergic reaction occurs.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Irinotecan may interact with other medicines, altering its efficacy or toxicity profile.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin): decrease irinotecan exposure.
• UGT1A1 inhibitors (e.g., atazanavir): increase SN‑38 levels and toxicity.
• Concurrent myelosuppressive agents: amplify risk of severe neutropenia.
• Anticholinergic drugs: may exacerbate irinotecan‑induced diarrhea.
• Live vaccines: immunosuppression may reduce vaccine effectiveness.

Moderate Interactions (Monitor Closely)

• CYP3A4 inhibitors (e.g., ketoconazole): raise irinotecan plasma concentrations.
• Anticoagulants (e.g., warfarin): heightened bleeding risk.
• Antidiarrheal agents (e.g., loperamide): may mask early signs of severe diarrhea.
• Proton pump inhibitors: possible alteration of gastric pH affecting absorption of oral metabolites.
• Herbal supplements (e.g., St. John’s wort): may induce metabolic enzymes.