I want you to understand the composition of Febrex plus. Febrex plus has three medicines (paracetamol for fever and chlorpheniramine, phenylephrine for cold) You mentioned your child had cold and cough for the past 5 days. If fever is not there, this medicine is not required. Only chlorpheniramine is enough for cold (watery runny nose symptoms). If nose secretions have become thick, even cold medicine can be stopped. Cough and cold get better by 7-8 days. If given in proper dose and schedule, side-effects are not usually seen. Sometimes child may feel sleepy because of chlorpheniramine.