• an autosomal dominant condition leading to a deficiency in uroporphyrinogen synthetase activity, causing an accumulation of uroporphobilogen, which is excreted in the urine turning it a dark color. Classic symptoms of an acute attack include intense abdominal pain, motor weakness, (usually starting proximally in the upper limbs) and confusion/agitation. These are due to nervous system dysfunction and demylenization. Diagnosis is by family history, increased levels of urinary porphobilogen, and deficient uroporphyrogen synthetase in the red blood cells. Treatment for an acute episode is supportive, including withdrawal of precipitating agents, carbohydrate support, hydration, and careful administration of hematin.
  • Many agents have been implemented as potential triggering agents for acute intermittent porphyria. The most commonly cited are barbiturates. Morphine, fentanyl and its conjoiners, and nitrous oxide are considered safe. Other anesthetic agents implicated as causative or exacerbative agents for AIP include most potent inhalation volatile anesthetics, benzodiazepines, ketamine, etomidate, meperidine, and lidocaine.