Irinotecan Hydrochloride

Indications

Irinotecan Injection is indicated as a component of first-line therapy in combination with 5-fluorouracil (5-FU) and leucovorin (LV) for patients with metastatic carcinoma of the colon or rectum.

Irinotecan is indicated for patients with metastatic carcinoma of the colon or rectum whose disease has recurred or progressed following initial fluorouracil-based therapy.

Pharmacology

Irinotecan inhibits the action of topoisomerase I. Irinotecan prevents religation of the DNA strand by binding to topoisomerase I-DNA complex. The formation of this ternary complex interferes with the moving replication fork, which induces replication arrest and lethal double-stranded breaks in DNA. As a result, DNA damage is not efficiently repaired and apoptosis (programmed cell death) occurs.

Dosage And Administration

Administer as a 90-minute intravenous infusion followed by LV and 5-FU. A reduction in the starting dose by one dose level may be considered for patients with any of the following conditions: prior pelvic/abdominal radiotherapy, performance status of 2, or increased bilirubin levels.

Refractory colorectal malignancies: 125 mg/m2 once wkly for 4 wk, followed by a 2 wk rest period.

Metastatic colorectal cancer: As 1st  line treatment: 125 mg/m2 on days 1,8,15 and 22 of a 6-wk cycle.

Interaction

Diuretics increase risks of dehydration secondary to vomiting/diarrhoea; prophylactic dexamethasone as an antiemetic may enhance lymphocytopenia; prochlorperazine may increase incidence of akathisia; antineoplastic agents (myelosuppression and diarrhoea). St John's wort, ketoconazole may reduce irinotecan exposure.

Contraindications

Patients with a known hypersensitivity to the drug or its excitements.

Side Effects

Anemia, Leukopenia, Neutropenia,Thrombocytopenia, Elevated bilirubin, Diarrhea, Nausea, Asthenia, Abdominal pain, Vomiting , Alopecia, Fever, Constipation, Anorexia, Mucositis, Pain, Dyspnea, Cough, Dizziness, Infection, Rash, Abdominal fullness, AST increased , Dyspepsia, Edema, Ascites/jaundice, Vasodilation, Thromboembolism, Hypotension, Neutropenic fever, Headache, Insomnia, Orthostatic hypotension

Pregnancy And Lactation

Pregnancy Category D. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

Precautions And Warnings

Early diarrhea is usually transient and infrequently severe. It may be accompanied by cholinergic symptoms of rhinitis, increased salivation, miosis, lacrimation, diaphoresis, flushing, and intestinal hyperperistalsis that can cause abdominal cramping. Bradycardia may also occur.

Late diarrhea can be life threatening since it may be prolonged and may lead to dehydration, electrolyte imbalance, or sepsis.Late diarrhea can be complicated by colitis, ulceration, bleeding, ileus, obstruction, and infection. Cases of megacolon and intestinal perforation have been reported.

Therapeutic Class

Cytotoxic Chemotherapy

Storage Conditions

Store at controlled room temperature 15° to 30°C. Protect from light. Keep the vial in the carton until the time of use.