Poison attacks deal initial damage, such as temporary ability damage or some other effect, to the opponent on a failed Fortitude save. Unless otherwise noted, another saving throw is required 1 minute later (regardless of the first save’s result) to avoid secondary damage. The Fortitude save against poison has a DC equal to 10 + 1/2 poisoning creature’s HD + poisoning creature’s Constitution modifier (the exact DC is given in the creature’s Species Traits). A successful save negates the damage.