This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous General Anesthesia, Subject name: Anaesthesia
Which anesthetic agent is contraindicated in porphyria: 
Select and explain. 
A. Propofol, B. Ketamine, C. Thiopentone, D. Etomidate
C: Thiopentone
Answer: C: Thiopentone 
Explanation: Ans: (c) ThiopentoneRef: KDT 6th ed./374* Thiopentone is an ultrashort acting thiobarbiturate because of rapid redistribution.* It has poor analgesic property.* I/v injection is very painful. Therefore it is contraindicated unless opioids or N2O has been given.* Contraindicated in porphyria patientsAlso Know*Etomidatei insufficiency.* Drugs safe in patients with porphyria: Propofol