[larskrygan]

how long do you think a toxin/poison  should last once injected into te body ?

in my opinion, it lasts until a succesfull first aid/medecine test is done , the threshold being the power of said toxin/poison.

how do you guys manage it ?

[voydangel]

SR4A pg. 254 under effects states exactly how long the various effects should last.

Edit: More specifically:
Disorientation is 10 minutes.
Nausea is incapacitation for 3 combat turns if the DV of the toxin > Willpower (after resistance test) & double all wound modifiers for 10 minutes.
Paralysis is 1 hour but only if the DV of the toxin > Reaction (after resistance test).
Some toxins have additional/special rules.