Cough and cold is seasonal. Also depending on the area and which strain is causing what picture we decide on medication. Physical examination is more important. Most of the viral cough and colds get corrected on their own. For nasal blockade u may use normal saline drops. Give paracetamol (15mg/kg) every 8 hourly. That reduces inflammation (even if there's no fever) Remaining decongestants are decided by your doctor on physical examination. And not safe to take without showing to doctor one