High sugar level. To gave 20 units.

My father is heart patient n dibetic too.he also have B.P. problem.Around 20 days before his sugar level reachto 45 at t time he had loose motion.he admitted in hospital n took treatment. Now he is discharged after two days.From that day his sugar level is very high.before fasting 336 n after451 . he was given medicine Zorly4,one morning n one evening, ondero5one morning...but sugar was approx same...then doc prescribed him insulin after1 week...Lantus solo star..he started wid 14 units .After 5 days sugar remain 325 to 400.doc advised to take 18 units .After 4 days sugar was 200 to 350.doc advised to gave 20 units...need ur advice on the insulin dose n further medication to cut t sugar at normal level ASAP...need ur views as he is a heart ,BP,n sugar patient. Is there any side effect of high sugar as so long.