This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
All the following drugs act on cannabinoid receptors except 
Select and explain. 
A. Nabilone, B. Rimonabant, C. Mescaline, D. Dronabinol
C: Mescaline
Answer: C: Mescaline 
Explanation: Mescaline does not act on cannabinoid receptors. Dronabinol and nabilone increase appetite and act as antiemetics. Rimonabant is banned now(D/T increased suicides) Mescaline is a naturally occuring hallucinogenic drug. Ref: KD Tripathi, 8th ed