Arsenic trioxide injection is indicated for treating acute promyelocytic leukaemia (APL) where a patient fails, or relapses from all-trans retinoic acid and anthracycline chemotherapy. Although results vary, complete remission occurs in over 85% of patients, but reduces over time.
Its effect is possibly by inducing partial differentiation and apoptosis of leukaemic cells; as well as the degradation of specific APL fusion transcripts, antiproliferation, and inhibition of angiogenesis.
AP differentiation syndrome is life-threatening and common. It is characterised by fever, dyspnea, weight gain, pulmonary infiltrates and pleural or pericardial effusions with or without leukocytosis. It generally resolves with high dose steroids and without the need to discontinue the arsenic. Adverse reactions are common, but usually mild, and resolve after discontinuation.
Arsenic is metabolised prior to slow renal elimination, so caution is recommended with renal or hepatic impairment. Deposits in liver, kidney, heart, lung, hair and nails increases gradually, and decline after withdrawal.
Arsenic trioxide should be used cautiously with congestive heart failure and hypokalaemia as they exacerbate QT interval prolongation. Monitor for signs of neuropathy.