Arsenic trioxide in the management of acute promyelocytic leukaemia.

Arsenical compounds were used as early as 2000 BC, both as medicines as well as poisons. Arsenicals gained importance in the beginning of the last century as the primary mode of treating syphilis. In 1931, Folkner and Scott used an arsenical preparation called Fowler's solution in the treatment of chronic myeloid leukaemia. This continued to be used until the introduction of busulphan in 1953. In the 1970s, arsenic trioxide was introduced for the treatment of acute promyelocytic leukaemia in China and was found to be extremely effective in treating this condition. Since then, numerous in vitro and in vivo studies have confirmed this observation. This article reviews the pathogenesis of acute promyelocytic leukaemia, the possible mechanism of action of arsenic trioxide in this condition and the literature on its use in the treatment, with special reference to the clinical and molecular response rates, toxicity and pharmacology of this compound. It also attempts to address the role of arsenic trioxide in the present algorithm for the treatment of acute promyelocytic leukaemia.