Pharmacology Of Arsenic trioxide

Indication For induction of remission and consolidation in patients with acute promyelocytic leukemia (APL), and whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression
Pharmacodynamics Arsenic Trioxide is indicated for induction of remission and consolidation in patients with acute promyelocytic leukemia (APL) who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy.
Mechanism of action The mechanism of action of Arsenic Trioxide is not completely understood. Arsenic trioxide causes morphological changes and DNA fragmentation characteristic of apoptosis in NB4 human promyelocytic leukemia cells in vitro. Arsenic trioxide also causes damage or degradation of the fusion protein PML/RAR-alpha. It is suspected that arsenic trioxide induces cancer cells to undergo apoptosis.
Absorption Not Available
Volume of distribution Not Available
Protein binding 75% bound
Metabolism The metabolism of arsenic trioxide involves reduction of pentavalent arsenic to trivalent arsenic by arsenate reductase and methylation of trivalent arsenic to monomethylarsonic acid and monomethylarsonic acid to dimethylarsinic acid by methyltransferases. The main site of methylation reactions appears to be the liver. Arsenic is stored mainly in liver, kidney, heart, lung, hair and nails.
Route of elimination Trivalent arsenic is mostly methylated in humans and excreted in urine.
Half life Not Available
Clearance Not Available
Toxicity Symptoms of overdose include convulsions, muscle weakness and confusion.