My 4.5 year old kept coughing last night and later spit up a load of white foam. His throat kept filling up while he was asleep.  He does have asthma.  I gave him his inhailor before going to bed.  Earlier he said he had a pain in his belly that he said was better before he went to  bed,
As you have discussed in your history your son is most probably suffering from upper respiratory tract infection. For this you can give him syrup moxikind-cv 5 ml three times daily or syrup azithromycin 200 mg 5 ml once daily along with tusked or syrup linctus 1 SF three times daily for cough with syrup paracetamol or syrup Cronin 5 ml s.o.s. if fever and pain is there. You can also nebulize your son with albuterol nebulizer at your family doctors clinic as it provides too much relief to your child.