Polycythaemia vera (PV)
The major goal of the treatment is to prevent thrombotic complications and haemorrhages. The amount of red blood cells is kept within the normal range (haematocrit < 0.45, haemoglobin < 145 g/l). This prevents cardiovascular deaths and thromboses . Allopurinol is the primary drug for preventing gout symptoms and hyperuricaemic kidney lesions if urate levels are at the upper end of the normal range. In thrombocytosis, a low dose of aspirin (100 mg/day) is given to reduce the risk of distal ischaemia and transcient ischaemic attacks. This dose is sufficient to reduce the risk of thrombosis in cerebral and coronary circulation .