Dear Dr Stephen, My son (5 yrs) old has been having frequent colds, blocked nose and chesty coughs with wheeze and few bronchitis . Previously his treatment included nebulizer , Ventolin syrup, anti-allergy syrup, cough syrup, nasal spray and antibiotic when needed. This time the doctor prescribed nasal spray, Fenistil drops and Gelobronchial for 7 days. Is Fenistil commonly used in colds? It makes my son very tired and his behaviour is nor good either.. Many thanks and regards,