4. Before Taking. It’s forbidden to use Lantus in case of having an allergy to insulin or a low blood sugar episode. Children under 6 years old can’t get Lantus. It also can’t be used for treating type 2 diabetes in children of any age. You should consult with your doctor if you have kidney/liver disease, hypokalemia, or diabetic ketoacidosis. It’s not recommended to change the brand of syringe or insulin glargine without consulting your doctor. Before injecting, always check the medicine label. Don’t drink alcohol when using Lantus, while it interferes with the diabetes treatment and might cause blood sugar reduction.