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
Thiopentone is C/I in: 
Select and explain. 
A. Acute intermittent porphyria, B. Bronchial Asthma, C. Both, D. None
A: Acute intermittent porphyria
Answer: A: Acute intermittent porphyria 
Explanation: A i.e. Acute intermittent porphyria - In porphyria (AIP), barbiturates (eg thiopentone, methohexital & thiamylal), etomidate, pentazocine and ropivacaine are avoided/ contraindicatedQ whereas diclofenac, ketorolac, phenacetin, tilidine, chlordiazepoxide, nitrazepam, hydralazine, nifedipine, and phenoxybenzamine are used with extreme caution only. Barbiturate (Thiopentone) induces aminolevulenic acid synthetase & formation of porphyrin which may precipitate actue intermittent or variegate prophyriaQ. ; so it is contraindicated in porphyria.Q - Due to cholinergic nerve stimulation, histamine release or direct bronchial smooth muscle stimulation, barbiturates may cause bronchospasm; which would be preventable by pretreatment with atropine, so it is not C/I in asthma.