What happens to the body if you truly substance abuse death drugs like cyanide, Nembutal, ricin? stuff that normally kills you from just 200mg, 2mg and 10ml.

Imagine swallowing 0.5liters of nembutal.

Plus various other medicine like cough syrup and hallucinogenic mushrooms.
You can die from drinking 5liters of water, imagine 5 liters of magnesium.