Footnotes

• Contributors Study concept: SMS. Clinical data acquisition: SB and YH. Drafting of the manuscript: SB. Critical revision of the manuscript for important intellectual content: ST and SMS.

• Funding Part of this work was undertaken at University College London Hospitals, who received a proportion of funding from the NIHR Biomedical Research Centres funding scheme. SB was supported by the Polytechnic University of Marche, Italy, for a 1-year research fellowship.

• Disclaimer In the report, the classifications given for drugs in terms of porphyrogenicity/non-porphyrogenicity are from the literature and generally based on clinical observations, and experimental or in vitro findings. In some cases, they are results of pharmacological considerations applied to a genometabolic model of acute porphyria. There are, however, potential sources of error in all presently available techniques for drug porphyrogenicity assessment. Even with care taken to eliminate them errors lege artis, it is not possible to take legal responsibility for the drug classifications provided and the data should not be taken as advice.

• Competing interests None declared.

• Patient consent Obtained.

• Provenance and peer review Not commissioned; externally peer reviewed. This paper was reviewed by Mark Manford, Cambridge, UK.