Acute porphyria: The drug demon etiology

Drugs are one of the important factors that precipitate acute attacks in patients with porphyria. Various in vitro and preclinical animal models exist for determining porphyrogenicity of a drug, but these predictions are not very reliable. Ambiguities still remain with many drugs as to whether they are safe in patients with porphyria. An algorithm for determining the porphyrogenic potential using evidence from anectodotal reports, lipophilicity, affinity of a drug to the Cytochrome enzymes (CYP450), ability to induce or irreversibly inhibit either CYP450 2C9 or CYP450 3A4 and the ability to induce hepatic 5-aminolevulinate synthase has been devised. Management of an acute attack of porphyria involves symptomatic treatment and administration of haem arginate. Several international networks have been initiated that serve as good sources of information for the safe use of drugs to be used in porphyria.