hold (one's) high
To be able to use drugs without becoming noticeably intoxicated or exhibiting other negative effects, such as becoming ill or unconscious. Similar in construction to "hold one's liquor." A: "You can always tell when Joe's smoked some weed because he starts acting all wacky." B: "Oh yeah, that guy really can't hold his high."
hold one’s high
tv. to behave reasonably well under the influence of drugs. (Similar to hold one’s liquor.) Ernie can’t hold his high. What a creep!