This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Substance abuse, Subject name: Psychiatry
Mainlining is seen in which of the following drug abuse in which the patient will inject drug into main veins 
Select and explain. 
A. Heroin, B. Cannabis, C. Cocaine, D. Morphine
D: Morphine
Answer: D: Morphine 
Explanation: Mainlining(SHIFT from peripheral to central vein injections) and skin popping(injecting SC) are seen in abuse of opioids opiod use is not a medical emergency like alcohol but opiod withdrawl is one of the ourite questions for examiners the famous quote that is used for describing opiod withdrawl is ALL ORIFICES BLEED WITH PUPILLARY DIALATION you need to inculcate the image of opiod withdrawl that is given in your mind to answer case scenario related questions. Ref: Essentials of postgraduate psychiatry By JN Vyas 1st ed Pg 338