Renewal is the only cure for draining. and it needs to be applied ASAP, or else you will slowly, permanently lose stats, HPS, MPS etc.
i am not sure how long you have, but have had great success with drinking a Renewal at the end of the battle and not losing anything.
however, my first time, i barely noticed it and lost nearly 55 HPS, 42 MPS and other things over the course of 3 gamedays. the blood drop was gone after about a gamehour, so i thot that i had been healed.
but i wasn't.
i had permanent losses but the Renewal pot at that late date stopped any further loss. silly me. i only noticed because all of a sudden my girl was unable to carry anything. her personal inventory had grown to be too heavy for her to even walk around.
yep, i learned my lesson, so i went back to an earlier save. now i keep one Renewal on everyone at all times. i still run into bat vampires and the like occassionally and don't wanna go thru that again.
V***V