In which of the following disorders, administration of barbiturates is contraindicated?: (A) Anxiety disorders, (B) Acute intermittent porphyria, (C) Kernicterus, (D) Refractory status epilepticus
Answer is B. Ans. (B) Acute intermittent porphyria(Ref: KDT 8/e p427)Barbiturates induce the rate limiting enzyme 'd-aminolaevulanic acid synthase' in porphyrin synthesis. This increased synthesis of porphyrins can precipitate acute attack of AIP.