This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Opioid-Related Disorders, Subject name: Psychiatry
Withdrawal of which of the following causes piloerecton ? 
Select and explain. 
A. Morphine, B. Cannabis, C. Smoking, D. Alcohol
A: Morphine
Answer: A: Morphine 
Explanation: Ans. is 'a' i.e., Morphine Morphine withdrawalo Manifestations of morphine withdrawal# Lacrimation# Anxiety & fear# Mydriasis# Diarrhea# Palpitation# Sweating# Restlessness# Insomnia# Dehydration# Rapid weight loss# Yawning# Gooseflash (Piloerection)# Abdominal colic# Rise in BP o Delirium and convulsions are not a characteristicfeatures (contrast barbiturates) and are seen only occasionally.o Treatment consists of withdraw! of morphine and substitution with oral methadone followed by gradual withdrawl of methodone.o Recently the NMDA antagonists and nitric oxide synthatase inhibitors have been found to block morphine tolerance and dependance.