tablets comes under category of NSAIDS I.e non -steroidal anti inflammatory drugs and they are used from fever
to various painful conditions . Your fathers death is not related or not due to the side effect or the overdose by this tablets , when u take the excessive dose of these tablets they will cause gastritis
and heart burn ..that's it , death is not reported in any body taking them , probable cause of death for your father due to heart disease
as your father is diabetic and hypertensive.
Take care bye...