Coat With Poison

Choose up to one weapon or piece of ammunition such as a bolt. The chosen items become covered in a viscous goo with a rancid smell. The next time the chosen weapon would hit a creature it deals an additional 2d6 poison damage. The damage dealt by the poison reduces the maximum hit points of the creature by the damage dealt. The reduction lasts until the creature finishes a full rest. 

At Higher Levels: When you cast this spell using a spell slot of 2nd or higher, the damage increases by 1d6 for each spell slot above 1st.