Uncommon side effects These may affect up to 1 in 100 people treated with Arixtra. • bruising or swelling (oedema) • feeling sick or being sick (nausea or vomiting) • chest pain • breathlessness • rash or itchy skin • oozing from operation wound site • fever • reduction or increase in the number of platelets (blood cells necessary for blood clotting) • increase in some chemicals (enzymes) produced by the liver.