Very rare side effects These may affect up to 1 in 10,000 people: • allergic reactions, inflammation of blood vessels (allergic vasculitis) • increased sensitivity to the sun causing skin rash • inflammation of the liver (hepatitis), yellowing of the skin (jaundice) • rapid and excessive weight gain caused by fluid retention • stomach pain, bloating, feeling sick (nausea), vomiting or diarrhoea • decrease in the amount of sodium in your blood.