Flexyx

Flexyx drugs: Camptosar

Camptosar - General Information:

Camptosar is an antineoplastic enzyme inhibitor primarily used in the treatment of colorectal cancer. Camptosar is a derivative of camptothecin. Camptosar inhibits the action of topoisomerase I. Camptosar prevents religation of the DNA strand by binding to topoisomerase I-DNA complex, and causes double-strand DNA breakage and cell death.

Pharmacology:

Camptosar is an antineoplastic enzyme inhibitor primarily used in the treatment of colorectal cancer. Camptosar 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. Camptosar 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 Camptosar 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 Camptosar or SN-38. Mammalian cells cannot efficiently repair these double-strand breaks. The precise contribution of SN-38 to the activity of Camptosar in humans is not known. Camptosar is cell cycle phase-specific (S-phase).

Camptosar for patients

Patients and patientsí caregivers should be informed of the expected toxic effects of CAMPTOSAR, particularly of its gastrointestinal complications, such as nausea, vomiting, abdominal cramping, diarrhea, and infection. Each patient should be instructed to have loperamide readily available and to begin treatment for late diarrhea (generally occurring more than 24 hours after administration of CAMPTOSAR) at the first episode of poorly formed or loose stools or the earliest onset of bowel movements more frequent than normally expected for the patient. One dosage regimen for loperamide used in clinical trials consisted of the following (Note: This dosage regimen exceeds the usual dosage recommendations for loperamide.): 4 mg at the first onset of late diarrhea and then 2 mg every 2 hours until the patient is diarrhea-free for at least 12 hours. During the night, the patient may take 4 mg of loperamide every 4 hours. Premedication with loperamide is not recommended. The use of drugs with laxative properties should be avoided because of the potential for exacerbation of diarrhea. Patients should be advised to contact their physician to discuss any laxative use.

Patients should be instructed to contact their physician or nurse if any of the following occur: diarrhea for the first time during treatment; black or bloody stools; symptoms of dehydration such as lightheadedness, dizziness, or faintness; inability to take fluids by mouth due to nausea or vomiting; inability to get diarrhea under control within 24 hours; or fever or evidence of infection.

Patients should be alerted to the possibility of alopecia.

Camptosar Interactions

The adverse effects of CAMPTOSAR, such as myelosuppression and diarrhea, would be expected to be exacerbated by other antineoplastic agents having similar adverse effects.

Patients who have previously received pelvic/ abdominal irradiation are at increased risk of severe myelosuppression following the administration of CAMPTOSAR. The concurrent administration of CAMPTOSAR with irradiation has not been adequately studied and is not recommended.

Lymphocytopenia has been reported in patients receiving CAMPTOSAR, and it is possible that the administration of dexamethasone as antiemetic prophylaxis may have enhanced the likelihood of this effect. However, serious opportunistic infections have not been observed, and no complications have specifically been attributed to lymphocytopenia.

Hyperglycemia has also been reported in patients receiving CAMPTOSAR. Usually, this has been observed in patients with a history of diabetes mellitus or evidence of glucose intolerance prior to administration of CAMPTOSAR. It is probable that dexamethasone, given as antiemetic prophylaxis, contributed to hyperglycemia in some patients.

The incidence of akathisia in clinical trials of the weekly dosage schedule was greater (8.5%, 4/47 patients) when prochlorperazine was administered on the same day as CAMPTOSAR than when these drugs were given on separate days (1.3%, 1/80 patients). The 8.5% incidence of akathisia, however, is within the range reported for use of prochlorperazine when given as a premedication for other chemotherapies.

It would be expected that laxative use during therapy with CAMPTOSAR would worsen the incidence or severity of diarrhea, but this has not been studied.

In view of the potential risk of dehydration secondary to vomiting and/or diarrhea induced by CAMPTOSAR, the physician may wish to withhold diuretics during dosing with CAMPTOSAR and, certainly, during periods of active vomiting or diarrhea.

Drug-Laboratory Test Interactions

There are no known interactions between CAMPTOSAR and laboratory tests.

Camptosar Contraindications

CAMPTOSAR Injection is contraindicated in patients with a known hypersensitivity to the drug.

Additional information about Camptosar

Camptosar Indication: For the treatment of metastatic colorectal cancer (first-line therapy when administered with 5-fluorouracil and leucovorin).
Mechanism Of Action: Camptosar inhibits the action of topoisomerase I. Camptosar prevents religation of the DNA strand by binding to topoisomerase I-DNA complex, and causes double-strand DNA breakage and cell death.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Irinotecan
Synonyms: Irinotecan Hydrochloride; Irinotecan Hydrochloride Trihydrate; Irinotecan Hcl; Irinotecanum [Inn-Latin]
Where to order Irinotecan (and Camptosar analogs) online:
Drug Category: Radiation-Sensitizing Agents; Prodrugs; Parasympathomimetics; Antineoplastic Agents; Enzyme Inhibitors
Drug Type: Small Molecule; Approved; Investigational
Other Brand Names containing Irinotecan: CP0; Camptosar; IRINOTECAN, CPT-11;
Absorption: 100%
Toxicity (Overdose): Gastrointestinal complications, such as nausea, vomiting, abdominal cramping, diarrhea, and infection.
Protein Binding: 30%-68%
Biotransformation: Hepatic
Half Life: 6-12 hours
Dosage Forms of Camptosar: Solution Intravenous
Chemical IUPAC Name: irinotecan hydrochloride
Chemical Formula: C33H38N4O6
Irinotecan on Wikipedia: http://en.wikipedia.org/wiki/Irinotecan
Organisms Affected: Humans and other mammals