Radioactive medicine reactions in children are rare. However, any child could experience one. Children at higher risk are those having: asthma, sensitivity to medicines or an allergen (anything that can cause an allergic reaction), heart failure and those less than 12 months of age.
Possible reactions are feeling warm, nausea, vomiting, hives, congestion, trouble breathing, apnea (stop breathing), chest pain and as with many given medicines there is a possibility of a severe reaction, which could result in death.