I find that it is pretty much impossible to drop severely
low in that period of time with
Lantus, if the dosage is correct and the last blood test was normal. It could be that the oral meds plus the Lantus are too much for him and his dosage needs to be adjusted. If it is happening often, have him test frequently for awhile and write down the results to he has a record of the patterns. Then he needs to work with his doctor to perhaps lower the dosage of one of the medicines.