‘Blood pressure drug does not trigger tumour in short term’
Valsartan, which can be prescribed under the brand name Diovan, was recalled in 22 countries, including the United States (U.S.) and United Kingdom (U.K.), in July.
A change in manufacturing in China caused N-Nitrosodimethylamine (NDMA) – a potent chemical also used in rocket fuel – to trickled into the supply.
Yet, a Danish study released last week found no link between NDMA exposure through valsartan and a person developing cancer over four years.
Researchers from the University of Southern Denmark analysed 5,150 people over 40 with no history of cancer.
The participants had taken valsartan at some point between 2012 and 2017.
Zhejiang Huahai Pharmaceuticals, a company in Linhai, east China, which manufactured the drug, changed its production process in 2012, which is thought to have led to NDMA contamination.
NDMA is one of the strongest known cancer-causing substances in animals, with health officials declaring it ‘probably carcinogenic to humans’.
Chemical exposure was calculated by identifying, via drug codes, the batches from which patients were prescribed valsartan.
National cancer registries determined the participants who were diagnosed with the disease around four years after they were prescribed the drug.
Results, published in the BMJ, suggest 104 of the participants developed cancer after taking valsartan contaminated with NDMA.
This is compared to 198 people who developed the disease and were not exposed to the chemical. This is not a significant difference.
The researchers stress, however, the study was only carried out over several years. NDMA-contaminated valsartan may therefore be linked to cancer if a person takes the drug long term.
Rita Banzi and Vittorio Bertele, from the Center for Drug Regulatory Policies in Milan, who were not involved in the research, said: “This study alone cannot dispel doubts about the potential risk for patients in the longer term, but it helps inform decision-making around this episode.
“It also illustrates the usefulness of national registries for examining the relations between risk factors and health problems and how research can give a prompt response whenever public health concerns emerge.”
The European Medicines Agency (EMA), which raised the alarm over valsartan on July 5, said it is working to establish how long, and at what levels, patients might have been exposed to NDMA.
Meanwhile, mothers with elevated blood glucose during pregnancy — even if not high enough to meet the traditional definition of gestational diabetes — were significantly more likely to have developed type 2 diabetes a decade after pregnancy than their counterparts without high blood glucose.
For children born to mothers with elevated or normal glucose, researchers found no statistically significant difference between the two groups of children in terms of their combined overweight and obesity, the study’s primary outcome.
However, when obesity was measured alone, children of mothers with elevated blood glucose were significantly more likely to be obese.