Neutralize poison
From Ardrana
By means of a neutralize poison spell, the priest detoxifies any sort of venom in the creature or substance touched. This spell can prevent death in a poisoned creature if cast before death occurs.
The reversed spell, poison, requires the caster to touch the victim, who is incapacitated and dies in a matter of minutes unless the poison is magically neutralized or slowed.
Note: This version of neutralize poison originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.