Low level mercury in drugs safe but EU needs to set limits say Polish researchers
The comments follow a study of drugs and supplements in Poland which found that, on average, prescription drugs in the country contain 23.3 nanogrammes of mercury per gram, while over-the-counter meds had 9 nanogrammes per gram.
Authors Marcin Frankowski from the Adam Mickiewicz University in Poznan said that, alone, the levels of mercury detected pose little health risk, pointing out that the concentrations found were lower than the WHO’s provisional tolerable weekly limit.
They also said that: “The most likely contaminant in those medications and supplements was inorganic mercury, the mono- and divalent cations. These are poorly absorbed through the intestine and…would be toxicologically insignificant.”
But Frankowski and Mickiewicz still think drug mercury content should be checked more regularly, arguing that because patients are also exposed to environmental sources of the metal those taking pills regularly could build up harmful accumulations of the metal.
“It should be noted that mercury is present not only in pharmaceuticals, but also in water, air, soil, plants and animals and together with drugs, it can pose a threat to the human body. Hence, measurements of mercury concentrations in medicines are necessary.”
Production concerns
The researchers also warned about the dangers posed by low quality active pharmaceutical ingredients (API), suggesting that although most “manufacturers of drugs and dietary supplements pay attention to the purity of the production” there are others that do not.
They wrote that "Low-quality raw materials, inadequate control during the production and drug counterfeiting can lead to high concentrations of mercury in the final product, which can pose a health threat to consumers, poisoning and even death."
To help address this, the authors also called on organizations such as the WHO, FAO and EFDA to introduce common sense limitations for mercury concentrations in drugs and dietary supplements.
Industry response
Commenting on the study, the European Federation of Pharmaceutical Industries and Associations (EFPIA) told us “In general it is possible to conclude that the levels assessed in medicines do not to pose a threat to human health as the values reported are well below the guidelines referred to in the paper.
The industry group added that: “This is especially clear, when compared with the most conservative limit provided by the WHO guideline, which applies to methyl mercury and is designed to protect pregnant women.”
EFPIA also questioned the authors’ call for a European Union-wide mercury limit to be set, arguing that existing International Conference on Harmonization (ICH) guidelines effectively establish such a definition.
“The paper suggests that permissible limits for mercury in medicines have not been defined in current European regulations. However, it does omit to mention that a globally applicable guideline, also adopted by the European Medicines Agency, is available, which defines limits for mercury (ICH Q3D, 2014) in medicinal products.”
The EMA notes that for inorganic (metal) mercury (impurity) safety limits can be found in the recently published ICH guideline Q3D here: http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2015/01/WC500180284.pdf
ICH guidelines are guidelines that are harmonised between Europe, Japan and the United States of America by the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use
Source: Regulatory toxicology and pharmacology
“Levels and potential health risks of mercury in prescription, non-prescription medicines and dietary supplements in Poland.”
Artur Kowalski and Marcin Frankowski
doi:10.1016/j.yrtph.2015.08.001
