you believe that the "loan" (i'd say "gift") is not for their drug of choice. yet, if this person is in active addiciton (currently using) then of course it IS because of the drug use.
we all have limited resources; we all decide every day how to use those resources. if any of this person's resources are going toward activity that is not in his/her best interest, then giving said person money, gas in the car, groceries, is called enabling