stoned

Being "stoned" is a state of altered awareness caused by some drugs. It is a side-effect of the drug: The primary reason a person takes the drug is to become "high," to be in a pleasurable state of being; when the high wears off, the person is left feeling stoned. Eventually the feeling of being stoned wears off and the person’s regular state of awareness resumes.
For some people, being stoned is a pleasant state; others people find it unpleasant.

"That morning Harry had waked and baked, then had hit the bong hard all day long, and now as twilight set in he was fully and righteously stoned off his ass."