Irinotecan Hydrochloride (3 brand names, 2 dosage forms, 2 routes)
Available dosage forms: INJECTABLE, INJECTABLE, LIPOSOMAL.
Routes of administration: INJECTION, INTRAVENOUS.
Brand Names
- CAMPTOSAR
- IRINOTECAN HYDROCHLORIDE
- ONIVYDE
Boxed Warning
• Early and late forms of diarrhea can occur. Early diarrhea may be accompanied by cholinergic symptoms which may be prevented or ameliorated by atropine. Late diarrhea can be life threatening and should be treated promptly with loperamide. Monitor patients with diarrhea and give fluid and electrolytes as needed. Institute antibiotic therapy if patients develop ileus, fever, or severe neutropenia. Interrupt CAMPTOSAR and reduce subsequent doses if severe diarrhea occurs [see Dosage and Administration (2.2) and Warnings and Precautions (5.1)]. • Severe myelosuppression may occur [see Warnings and Precautions (5.2)].
Indications and Usage
•CAMPTOSAR 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. •CAMPTOSAR is indicated for patients with metastatic carcinoma of the colon or rectum whose disease has recurred or progressed following initial fluorouracil-based therapy.
Contraindications
•CAMPTOSAR Injection is contraindicated in patients with a known hypersensitivity to the drug or its excipients.
Mechanism of Action
Irinotecan is a derivative of camptothecin. Camptothecins interact specifically with the enzyme topoisomerase I, which relieves torsional strain in DNA by inducing reversible single-strand breaks. Irinotecan and its active metabolite SN-38 bind to the topoisomerase I-DNA complex and prevent religation of these single-strand breaks. Current research suggests that the cytotoxicity of irinotecan is due to double-strand DNA damage produced during DNA synthesis when replication enzymes interact with the ternary complex formed by topoisomerase I, DNA, and either irinotecan or SN-38. Mammalian cells cannot efficiently repair these double-strand breaks.
Overdosage
In U.S. phase 1 trials, single doses of up to 345 mg/m2 of irinotecan were administered to patients with various cancers. Single doses of up to 750 mg/m2 of irinotecan have been given in non-U.S. trials. The adverse events in these patients were similar to those reported with the recommended dosage and regimen. There have been reports of overdosage at doses up to approximately twice the recommended therapeutic dose, which may be fatal. The most significant adverse reactions reported were severe neutropenia and severe diarrhea. There is no known antidote for overdosage of CAMPTOSAR. Maximum supportive care should be instituted to prevent dehydration due to diarrhea and to treat any infectious complications.