Arsenic trioxide

Arsenic trioxide

Arsenic trioxide is a commercially available treatment for pa-tients with acute promyelocytic leukemia (a rare form of acute myeloid leukemia). It’s indicated when standard therapy has failed.

Pharmacokinetics

Arsenic trioxide is administered I.V. because it’s inadequately ab-sorbed orally. The metabolism of arsenic trioxide involves reduc-tion via arsenate reductase, with subsequent methylation to inac-tive metabolites in urine. Arsenic is distributed in the heart, liver, kidney, lung, hair, and nails. (See Preventng the fatal effects of ar-senic.)

Pharmacodynamics

Arsenic trioxide causes DNA fragmentation.

Pharmacotherapeutics

Arsenic trioxide is used to treat acute promyelocytic leukemia that has relapsed after standard chemotherapy. It’s also being in-vestigated for treatment of multiple myeloma.

Drug interactions

Giving arsenic trioxide with other drugs known to prolong the QT interval may increase the risk of cardiac arrhythmias. (See Ad-verse reactions to arsenic trioxide.)