Gliclazide is one of the medications which can cause hypos, and so should have been prescribed along with a meter and strips.
I have no personal experience of it, but would advise monitoring carefully if the tablet is taken early in the day with no food - if he is travelling to work it could be an essential safeguard.
It could be intended to deal with dawn phenomenon, which is not dependant on food - but as levels of blood glucose fall - hopefully but particularly if a low carb diet is being followed - so low levels could result easily and quickly. Why it was dictated that a tablet be taken first thing without explanation of the reasoning is rather concerning. Of course, there could be no reason for it, but I'm just rather cynical these days.
I believe that the DVLA needs to be informed if a driver is taking Gliclazide, and perhaps the insurer of the vehicle too.