How does a syenite pill work and how fast does it kill you?

Question

How does a syenite pill work and how fast does it kill you?

Answer 1

Cyanide is a group of chemicals where some are toxic and some are not. The most deadly are the hydrogen cyanides. When these are ingested they inhibit the abilit for a cell to use aerobic resperation, or make energy. This especially effects the CNS and cardiovascular system. If an antidote is not given in time and the right amount of cyanide is ingested, death is almost certain.

Answer 2

Do you mean cyanide?

I could go into biochemical detail, but in a nutshell it stops your cells from metabolising by non-reversibly binding to one of the components of it.  Kills pretty fast, but we need a dose to work out.