levels of 400+ are alarming and could be you at risk of diabetic coma caused by diabetic ketosis. No, these meds are not sufficient under such case. Insulin should be used. You need immediate treatment in this case.
To manage blood sugars you need medication (probably insulin) combined with low carb diet and exercise. Do not eat sweets, breads, rice, candies, fruit, fruit juice when your sugars are so high.
If you are feeling very bad or if the sugars do not go down to the 100s within a few hours please go to the ER for immediate treatment. IN any case contact your doctor asap.
When your sugars are so high you should also drink plenty of water as your kidneys are under verh high strain and are excreting the sugar.
When are you seeing " 400+count of sugar"? If at fasting, levels this high usually warrants the addition of insulin. At other times it is always in the best interest of the patient to consult with their primary care physician regarding adjustments/additions to existing medications. Keep in mind levels this high are dangerous to your well being. Try to eat a proper diabetic diet low in carbs and excluding sugary foods/drinks, maintain normal body weight & lipid panels, and perform 30-60 minutes of daily exercise [walking is good]. These all help in lowering blood sugar levels. Good luck -