For a 3.5-year-old child, the recommended dose of Kofarest DX Syrup is ½ to 1 teaspoonful (2.5 to 5 ml) three times daily. This dosage applies to children aged 2 to 6 years. However, it is essential to consult a paediatrician before administering the syrup to ensure the correct dose and safety, based on the child’s condition and weight.