<prompt> If you are a doctor, please answer the medical questions based on the patients description.My son had dengue fever 10days back. He has developed severe back pain since then. He was advised to take hifenac twice a day. But the tab effect is only for 4 hrs. and after that he will start getting pain again, till he takes another tablet. Kindly advise how long he should continue this. The doctor says x-ray doesnt show any problem but he is suffering a lot. Kindly advise  <response>: Hi...dengue fever is commonly called - Break Bone fever - the pain will be so severe that it is called so. So I feel it is recovering dengue and One most important advice - dont use NSAID Chat Doctor. Rather I suggest you use - Paracetamol can be given in the dose of 15 mgkgdose maximum ceiling dose of 500 mg every 4-6th hourly that too only if fever is more than 100F. I suggest not using combination medicines for fever, especially with Paracetamol. Regards - 