Singapore Drugs Database

Indication

Used in combination with infusional 5-FU/LV, is indicated for the treatment of advanced carcinoma of the colon or rectum and for adjuvant treatment of stage III colon cancer patients who have undergone complete resection of the primary tumor.

Mechanism of Action

Oxaliplatin undergoes nonenzymatic conversion to active derivatives via displacement of the labile oxalate ligand. Several transient reactive species are formed, including monoaquo and diaquo DACH platinum, which covalently bind with macromolecules. After activation, oxaliplatin binds preferentially to the guanine and cytosine moieties of DNA, leading to cross-linking of DNA, thus inhibiting DNA synthesis and transcription. Cytotoxicity is cell-cycle nonspecific.

Pharmacokinetics

Absorption

Bioavailability is complete following intravenous administration. When a single 2-hour intravenous infusion of oxaliplatin at a dose of 85 mg/m^2 is given, the peak serum concentration was 0.814 mcg/mL.

Distribution

* 440 L [single 2-hour IV infusion at dose of 85 mg/m^2] At the end of a 2-hour infusion of oxaliplatin, approximately 15% of the administered platinum is present in the systemic circulation. The remaining 85% is rapidly distributed into tissues or eliminated in the urine.

Metabolism

Oxaliplatin undergoes nonenzymatic conversion in physiologic solutions to active derivatives via displacement of the labile oxalate ligand. Several transient reactive species are formed, including monoaquo and diaquo DACH platinum, which covalently bind with macromolecules. There is no evidence of cytochrome P450-mediated metabolism in vitro.

Elimination

Clearance

* 10 - 17 L/h [renal clearance]

Toxicity

There have been five cases of oxaliplatin overdose reported. One patient received two 130 mg/m2 doses of oxaliplatin (cumulative dose of 260 mg/m²) within a 24-hour period. The patient experienced Grade 4 thrombocytopenia (3) without any bleeding, which resolved. Two other patients were mistakenly administered oxaliplatin instead of carboplatin. One patient received a total oxaliplatin dose of 500 mg and the other received 650 mg. The first patient experienced dyspnea, wheezing, paresthesia, profuse vomiting and chest pain on the day of administration. She developed respiratory failure and severe bradycardia, and subsequently did not respond to resuscitation efforts. The other patient also experienced dyspnea, wheezing, paresthesia, and vomiting. Most common adverse reactions (incidence ≥ 40%) were peripheral sensory neuropathy, neutropenia, thrombocytopenia, anemia, nausea, increase in transaminases and alkaline phosphatase, diarrhea, emesis, fatigue and stomatitis.

Active Ingredient/Synonyms

Diaminocyclohexane Oxalatoplatinum | L-OHP | Oxalatoplatin | Oxalatoplatinum | oxaliplatine | oxaliplatino | oxaliplatinum | Oxaliplatin |