Lantus (insulin Glargine) is a very SLOW release insulin, a so-called "24-hour" insulin. Because it does not rapidly alter glucose levels it is safe to use when driving. It isn't adviseable to increase the dose of Metformin. Other insulins have the tendency to rapidly (comparatively) alter levels of conscious and situational awareness. It is often prescribed together with Metformin and Glipozide. I would also hazard a guess that weight control is an issue. Loss of thirty pounds or more may solve the problem.
Your husband needs to be on insulin. Often LANTUS is enough to do the job. The CDL medicals are a standing joke, as are the FAA medicals. Years ago I required a First Class FAA medical for jets and I got mine on pass from a hospital where I was released from the intensive care unit AMA (against medical advice) long enough to make the appointment, before I collapsed. I "passed". All that being said, diabetes and truck driving don't mix well. The insidious onset of a diabetic coma results in a period of less than optimum awareness. Not something that is helpful when you have 80,000 pounds on the fifth whee and a schedule to make. I would suggest prescription LANTUS. I would also never every recommend that he do something that would violate CFR regulations by concealing the fact he is taking Lantus with an insulin syringe. My own opinion is that use of Lantus together with Metformin, together with exercise and tight dietary control (and I mean tight) would not unduly hazard the general public.
Agree, I think its time your husband got put on insulin.
Forgot to add that I strongly suggest he see an endocrinologist who will help him manage his diabetes; his doctor obviously does not know how to do so.
I'm sorry but if your husband's glucose level has been over 200 for the last 5 years he is in line to lose a lot more than his job! Diabetic complications from prolonged highs are not pretty, and studies show those complications start with prolonged numbers lower than that. What is wrong with his doctor that he would keep him on the same medication regimen for so long with no results?? If oral meds are no longer working it is time for him to start insulin. It's past time imho. THAT is what will get his numbers down, save his job and possibly his legs, eyesite and kidneys as well.