Flexon is the brand name of a combination product that contains ibuprofen 400 mg with paracetamol 500 mg. It is not clinically correct to give Fixed-Dose Combinations (FDCs) of two or more drugs, particularly to children. If at all a patient needs two medicines, they should be given individually in appropriate dose.
The problem with FDCs is that (a) dose cannot be individualised and (b) adverse effects get added up. For example ibuprofen cannot be given to people who have allergies such as bronchospasm that can soon progress to asthma but the same person can be given paracetamol. You may be interested to know that the National Commission on Macroeconomics and Health appointed by the Ministry of Health in its just release report has described paracetamol+ibuprofen combination as irrational, hazardous.
Unfortunately many doctors under the influence of drug companies continue to prescribe brands that help manufacturers more and patients less. The Government is equally at fault for allowing the manufacture and sale of irrational combinations such as Flexon.
I think you should take up the issue of indiscriminate medication to children. If at all a fever lowering or pain killer is required, simple agents such as paracetamol (sold as Crocin, Calpol etc) are relatively safer.