Safe prescribing in the autosomal dominant acute porphyrias: a practical approach: Part I

SummaryThe autosomal dominant acute hepatic porphyrias – principally acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria – can present with potentially fatal acute neurological crisis as a consequence of exposure to various precipitants including legal and illegal drugs. Information from clinical experience, and animal and cell culture experiments as well as pharmacological assessment is used to predict the likelihood that a drug may trigger an acute attack and whether it should be avoided. European specialist services have agreed a common approach, with the development of a searchable drug database, that classifies risk according to standard categories. It is usually possible to choose a well tolerated drug, but there remain situations in which a drug is required for which safety data are absent or conflicting; there are also rare circumstances wherein the clinical benefit of using an unsafe medication in a porphyria patient outweighs the risk. A clinical porphyria specialist can provide help in these circumstances.