The pharmacotherapy of sickle cell disease.

Sickle cell disease (SCD) is characterized by acute and chronic complications, which can affect almost any organ system in the body. Recently, there has been remarkable progress in the pharmacotherapy of SCD, and therapeutic options have been greatly expanded beyond red blood cell transfusion and hematopoietic stem cell transplantation. The most successful approach has been the stimulation of Hb F production through drugs such as hydroxycarbamide, which reduces the frequency of vaso-occlusive pain events and is the only therapeutic agent at present approved by the US Food and Drug Administration for SCD. Hydroxycarbamide is still greatly underused, but its indications are being broadened through a number of Phase II and III clinical trials. Other Hb F-promoting agents such as decitabine and butyrate have been studied less extensively. Another approach is the use of agents that reduce red cell dehydration through blockage of ion channels in the red cell membrane. Also under investigation is manipulation of nitric oxide (NO) metabolism to counteract the effects of chronic hemolysis. As yet, unproven drugs include agents that target coagulation, inflammation and adhesion to vascular endothelium. In the near future we expect to see exploration of the efficacy of drug combinations and an expansion in the use of the proven therapeutic, hydroxycarbamide.