Your prescribing doctor should have advised you how many units of actrapid and Lantus you should be taking and how many times through the day! It is different for each individual and it is not one specific treatment. As you are on Lantus insulin which is a Sanofi product, I suggest you contact them, they have a diabetes educator who can come home and visit the child and educate more about insulin, how to take, when to take, sugar alterations, insulin requirements with different diets and so on.