As anyone tried overdosing on amlodipine blood pressure tablets, or maybe everyone is so young there not on anything like that??
IMO, it's not an ideal way to CTB.
Firstly, as Pfizer mentioned in the manual, the LD50(It means when reaching this dose, half of the test animals died) of mouse is 683mg/kg, do the simple math then you'll clearly see that for human, the amount of pills you have to take would be unimaginable.
Secondly, in the case reports of human accidentally overdose and died, the main causes of death included multiple organ failure and Rhabdomyolysis, which means days even weeks of suffering under involuntary hospitalization, and chances are you might be awake during the process.
So in short, don't try this method, it's unreliable and extremely painful.
Wish you well, but this is not a good idea.