What do you recommend if i gave my son twice after evry 8hours tempra (acetaminophen) and neozep,just realized both are paracetamol?

Don't worry: It is very likely you have not harmed your child, so don't worry. Paracetamol (Acetaminophen) has a typical recommended dose of 15 mg/kg and it is not toxic to the liver until close to 150 mg/kg. In general, parents are advised to give 15mg/kg (for fever or pain), every 4 hours. The American Academy of Pediatrics no longer recommends cough/decongestant medications for children under 4 yrs.