You detoxify any sort of venom in the creature or object touched. A poisoned creature suffers no additional effects from the Poison, and any temporary effects are ended, but the spell does not reverse instantaneous effects, such as hit point damage, temporary ability damage, or effects that don’t go away on their own.
The creature is immune to any Poison it is exposed to during the duration of the spell, e.g. Troglodyte Stench. (bugged at present - no immunity, not even resistance. taking full poison damage.)