British tourists are being warned about a drug banned in the UK but commonly used by Spanish doctors. Metamizole, commonly sold under the brand Nolotil, is feared to be linked to dozens of deaths among British tourists and expats in Spain – and is banned in some 40 countries.

In rare cases, this pain relief method can cause a condition known as agranulocytosis, which depletes white blood cells, increasing in turn the risk of sepsis and even organ failure.

It is feared British people are more vulnerable to the drug’s dangerous side effects, but a 2016 study reportedly finding UK nationals were “80 to 120 times” more at risk than Spanish people has never been published.

Experts said not enough evidence has been gathered to support this theory and that more work needs to be done. 

Cristina Garcia del Campo, president of the Association for Drug Affected People (ADAF) and anti-Nolotil campaigner, claimed to know of dozens of Britons who have died after being given the drug since 2016.

Among them, she mentioned Mark Brooks, a father-of-one based in Alicante who died only days after being given an injection of metamizole to deal with shoulder pain.

His partner Summer Moses obtained Mr Brooks’ medical notes following his death and, as reported by the Observer, the first page of the documents stated: “Apparent allergic reaction to metamizole.”

Ms Del Campo said to have gathered evidence of more than 100 cases where British patients suffered adverse side effects after being given the controversial drug. 

The campaigner said health authorities were left “speechless” after she presented her evidence on the drug, and claimed they agreed the information suggested the populations were at greater risk.

However, Ms Del Campo told the MailOnline that only “weak recommendations” were made.

In 2018, a government directive advised health facilities to stop prescribing this medicine without a prescription. But as recently as in late 2023, the Observer newspaper claimed to have been able to purchase two packets of Nolotil at a chemist in the coastal town of Jávea – beloved by British expats – without prescription.

The campaigner is determined to continue her fight, as she believes “more and more people are going to die” unless something is done. 

She has now brought a criminal complaint of negligence to the public prosecutor.

The filing claimed the “Spanish Agency for Medicines and Health Products and of the different health administrations in charge of pharmacovigilance in Spain, or people in charge of patient safety in pharmacology are not responsibly doing their job”. It also called on Spanish health officials to “urgently initiate a thorough investigation into the matter”.

A spokesperson for Boehringer Ingelheim, the manufacturer that makes Nolotil, said in a statement to the MailOnline: “We take patient safety and public health seriously and closely cooperate with the regulators on product safety-related topics. We are of the opinion that current approved prescribing information adequately addresses current knowledge about identified risks.”

Express.co.uk has contacted the Spanish Health Ministry, the Spanish Agency for Medicines and Health Products and Boehringer Ingelheim for comment.