My son is 5 years old, he has a dry cough that has been for a week now and he sometimes pukes, he is also taking cold medicine for the cough, what can i do?

Viruses can last 5-10 days. Make sure he stays well hydrated, gets plenty of rest, and eats light meals. Be careful of giving cold meds to children under 6 as they can have adverse effects and usually don't do much for the symptoms. Remember that coughs may persist even once the other symptoms are gone. Use a humidifier in his room and have him take warm, steamy baths to hydrate any mucus.

It is not unusual for a viral cough to linger. If it continues for another week without beginning to resolve, I would take him back to see his primary care doctor or pediatrician. Good luck.