My daughter has had type 1 for almost one year now. If there were a few things I knew from the get go, life would have been a bit easier. My daughter gets Lantus in the morning as soon as she wakes up. Then she gets Humalog to cover her breakfast and correct her if necessary. There is no problem giving those two meds back to back. HOWEVER, make sure you do not dose the Humalog (or fast acting) any sooner then 2 hours of each other. Also, it helps not to dose Humalog after 7 or 8 p.m. unless your child is over 275. The most important thing no one ever told me not to dose Humalog and then let your child get a bath. Always wait at least 1-2 hours after being dosed before bath time, if you do not they will drop very low.
Of course, I am not a doctor but when you are a mother of a diabetic sometimes you know more because you live with child. Every kid is different but maybe this could help if you brought these ideas up to your dr.
Once the blood sugar levels are under control, his appetite will slow down some, so hang in there. He is hungry when glucose levels are high because his body is starving for those carb sugars that aren't being converted properly into energy. Hence, he craves food. This will be better once he is under control.
The high levels at night are probably happening because the evening Lantus is not truly lasting 24 hours. See if this makes sense to you... Lantus is marketed as a 24-hour insulin, but it doesn't work full force for exactly 24 hours and then -- poof -- suddenly quit. If you read the paperwork in your Lantus box, you will read that it lasts anywhere between 20-24 hours. It seems to peter out sort of slowly sometime in that time frame, leaving very little Lantus working to help with his dinner-time quick-acting insulin. So it may take more insulin in the evenings than at other mealtimes to cover the same amount of carbs.
Some of us prefer to split the Lantus dose, taking some in the morning and some in the evening to equal the complete dose. That way, only half is petering out after 20 hours, and the sugar levels stay more even throughout the day.
The Lantus shouldn't work quickly, for it crystallizes in the injection site and slowly dumps tiny bits of insulin into the body all day. So the quick-acting insulin is what you want to use to lower a high reading. You need to wait about 2-3 hours after the quick-acting insulin is given, though, before adding more, for it may still be peaking in action and you don't want to overdose, especially at night. Frankly, if in doubt at bedtime, I think it is safer to err on the side of slightly high than low, for lows in our sleep are very dangerous.
I hope this helps educate you some. I love the Lantus insulin, and the great control it offers, in conjunction with quick-acting insulin at mealtimes.