Avandamet is an Avandia/metformin combination. I'd certainly check with his doctor to see if he should continue it, as there has been some cardiac problems linked to Avandia in the news recently.
Is your husband getting regular exercise? Exercise helps with blood sugar control.
Personally, I have found that if I eat a lower carb diet, avoiding bread, potatoes, rice, pasta (all the good stuff), I have better readings. I eat lots of green veggies, lean meats, salads and try and stay away from the other things.
Does he monitor his blood sugar regularly to see how certain foods affect him? If he takes his blood sugar 2 hrs after his meals, he'll know what to avoid and what to eat based on his levels.