Rare side effects These may affect up to 1 in 1,000 people: • fluid in the lungs (pulmonary oedema) causing breathlessness • swelling of the retina at the back of the eye (macular oedema) • reduction in the number of red blood cells, or a type of white blood cell (granulocytopaenia) which can be severe (agranulocytosis), reduction in the number of all types of blood cells (pancytopaenia) • liver doesn’ t function as well as it should (increase in liver enzymes).