Information about
The Drug Database for Acute Porphyria


Atle Brun, MD, PhD
Norwegian Porphyria Centre (NAPOS)
Chair of the EPNET drugs working group

The Nordic Drug Database and the EPNET project

Many therapeutic drugs may precipitate attacks in acute porphyrias. The Nordic Drug Database for Acute Porphyria is a web-based searchable resource specifically designed for use by health care professionals in prescribing drugs and counselling patients who are carriers of an acute porphyria. The Norwegian Porphyria Centre (NAPOS) has, over a six year period, been responsible for the development of this multi-language database. Safety classification of drugs is a done in cooperation between Porphyria Centre Sweden and the Norwegian Porphyria Centre (NAPOS).

Presently the database contains information on about 1000 generic substances. The Nordic drug database is collaborating with EPNET. The European Porphyria Network (EPNET) is a project receiving funding from the European Union in the framework of the Public Health Programme. The aim of the EPNET project is to set up a functional network of specialist porphyria centres in Europe to provide better healthcare for porphyria patients and their families. One of the four strategic objectives of EPNET is to provide improved, evidence-based information about the selection of safe drugs for use in patients with an acute porphyria and to disseminate this improved information to most of the European Community. Increased accessibility to The Drug Database for Acute Porphyria will make it much easier for patients and physicians to select safe drugs and thereby minimise the risk of patients suffering a drug-induced attack. More information can be found under the EPNET info header of this database.

Method for drug safety classification

Currently the drugs in the database are classified according to a standardised method for assessment of the risk that a certain drug may activate the porphyric disease. This method is described in the paper: Guide to porphyrogenicity prediction and drug prescription in the acute porphyrias by Stig Thunell, Erik Pomp and Atle Brun. Br J Clin Pharm 2007;64(5):668-79  [ PMID 17578481]. It also allows risk assessments for drugs lacking porphyria related clinical experience. Some drugs in the database were classified during a period before the method for classification had been developed to its final version. Systematic revisions of complete drug groups are therefore now being done and the clinical information collected by the EPNET project will be added to that which is currently available.

Evidence and rationale for classification

For all drugs that are classified as ‘safe’ in the database, information about the rationale and evidence behind its classification is also available. This information displays when clicking the “Info” hyperlink button. A drug porphyrinogenicity monograph for the drug in question is given and contains relevant background information collected so far. This way the drug database is not only a practical clinical tool providing the safest drug alternative at a glance, but also contains valuable in-depth information, primarily of interest for porphyria specialists. This transparency of the database will hopefully stimulate to an increased reporting concerning drug tolerance and intolerance.
The recently launched European Porphyria Network (EPNET) program will be a major step forward to increasing the number of clinical drug reports. The aim is to collect 4000 reports in the project period (2007-2010).


User-friendliness has been emphasised in the development of the database. This web-resource is not only a list but contains a search engine allowing searches using trade names as well as generic names. Checking the safety of a drug is simply done by typing in the drug name or part of the drug name (the system uses automatically wildcard searching.) If the drug that is checked turns out to be classified as porphyrinogenic, a safer alternative should be sought. In this situation a safer drug can usually be found by simply pressing the “Show alternative drugs”-button. For optimal readability, different colour codes represent the five different drug risk-groups. Dropdown boxes are utilised for trade name synonyms to minimise screen listing. In the drug database the porphyrinogenicity classification is linked to the pharmaceutical Anatomic Therapeutic Classification codes (ATC-codes) of the drugs (a drug classification system recommended by WHO). This allows different classifications of one substance depending on its use (e.g. systemic use and topical use may be classified differently). Compared to drug lists based on only the generic name of the substance, linking of porphyrinogenicity classification to ATC-codes is clearly an advantage.

Expert advice on the web

Everyday standard treatment with drugs sometimes turns into a problem because the patient has been diagnosed with an acute porphyria and none of the recommended drugs for treatment of the patient’s disease are classified as safe. The benefit from using a drug should always be assessed against the risk of provoking an acute attack and the likely consequences of not using it. For more serious illnesses i.e. cancer, a drug treatment should be started. Before prescribing a potentially dangerous drug, it is recommended to seek advice from a porphyria specialist concerning the need for preventive measures and clinical and biochemical follow-up. The problem is that porphyria specialists are not available on the telephone 24 hours a day. A system for patient-specific advice has therefore been developed and is included in The Drug Database for Acute Porphyria. The database combines clinical data from the patient with the porphyrinogenicity classification of the drug and gives advice for a particular patient concerning the use of the drug, follow-up, and preventive measures.

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