Children often suffer from common cold which is caused by certain viruses. Often there could be secondary infections leading to yellow nasal secretions. Flumed is a medicine, the composition of which varies with the country in which it is being marketed. I assume that in your country it contains an antiallergic (Dexchlorpheniramine) which should make it right to be given. Please check if that is the composition. Alternatively, you can give some other antiallergic. Other than that you need to give steam inhalation. Just sit with the child in your lap and place the source of steam before you. The water vapour would be in the air and the child will automatically breathe it in. It will help in diluting the cough. You may also give saline drop in case nasal blockage occurs. I do not think that antibiotics would be required unless it lasts more than 7 days.