This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
In porphyria all drugs are safe except – 
Select and explain. 
A. Propofol, B. Midazolam, C. Afentanyl, D. Pentazocin
D: Pentazocin
Answer: D: Pentazocin 
Explanation: Pentazocin is considered unsafe, but other opioids including morphine, codeine, pethidine, fentanyl, Alfentanil and naloxone have been used safely. Propofol and benzodiazepines (midazolam) are safe.