*2.1.1 Mechanism involved or pathophysiology of the drug-induced aplastic anemia*

The underlying mechanism to induce the aplastic anemia is the activation of the immune complex by these suspected drugs and the patient's own immune system is directed toward the bone marrow. The immune related injury to the bone marrow will results in the synthesis of limited number of blood cells (hypoplastic anemia) or sometime make them almost empty (aplastic anemia).

Another hypothesis states that there is the generation of the intermediate toxic compounds that binds to several functional proteins and deoxyribose-nuclease acid (DNA) of these hematopoietic bone marrow cells leading to the direct injury of bone marrow. However, the generation of these toxic intermediate is highly dependent to the genetic variability of an individual. Some of the other research suggests the generation of toxic intermediates as an idiosyncratic condition.
