Possible Clues:

• Confusion with drug he's changed for another?
• Alternative spelling for resin obtained from the hem plant
• It's an unusual variant of cannibas
• Pipe filler
• He’s swallowing a novel hospital drug
• 'The ___ Eater' (19th-century memoir describing altered consciousness)
• Smoked drug
• Fudge ingredient in 'The Alice B. Toklas Cookbook'
• Intoxicating hemp extract
• Weed