There have been growing calls for a comprehensive national study in Spain to establish the adverse side-effects of the controversial painkiller metamizole, linked to a growing number of deaths in the country – particularly of Britons.
Packaged with warnings about dangerous side effects, the drug, sold under the name Nolotil, has been banned in more than 30 countries, but is available in South Africa.
Founder of campaign group the Association of Drug Affected Patients (ADAF) Cristina García del Campo said that most of the cases of adverse drug reactions from metamizole are never reported.
“Until a proper study is done, they should withdraw the drug,” she told The Guardian.
In November last year, MedicalBrief reported that a patients group representing several British victims had launched legal action against the Spanish government over claims that it failed to safeguard people against the potentially fatal side effects of the painkiller: serious illnesses, sepsis, amputations – and death.
Metamizole, said the report, can cause a condition known as agranulocytosis, which reduces white blood cells, increasing the risk of potentially fatal infection.
One Spanish regional Health Department has already warned that the drug should not be a first-choice painkiller, because of the risk of adverse side-effects.
There have been more than 40 deaths – many of them Britons – in the country, in which metamizole may have been responsible, and case reports in medical journals suggest certain populations may be more susceptible to the side-effects.
Iven metamizole. Her white cells were depleted and she died in April 2018 of organ failure.
Spain’s medicine and health products agency, the AEMPS, says the risk of agranulocytosis from metamizole, in which white blood cells are severely depleted, is very rare, in the range of one to 10 cases per million users. It says the benefits of the popular painkiller outweigh the risk.
There are, however, significant variations in these estimates. When the drug was withdrawn in Sweden in 1999, regulators estimated the risk of agranulocytosis at about one in every 2 000 prescriptions, with a mortality rate of 26%, concluding that the benefit-risk profile was unfavourable.
The reasons for these variations are unclear, but some research has suggested certain populations may be more susceptible to adverse reactions.
A 2009 study at the Costa del Sol Hospital in Marbella concluded: “Dipyrone-related agranulocytosis is an adverse effect more frequent in [the] British population, and its use must be avoided.”
Boehringer Ingelheim, which makes Nolotil, says other adverse side-effects, including infections, are listed on the drug information sheet. It says the current prescribing information “adequately addresses current knowledge about risks”.
The drug should only be available in Spain on prescription, but in November The Observer was able to buy two packets of Nolotil at a chemist on the Costa Blanca for less than €4, without a prescription.
Vicente Palop Larrea, a doctor specialising in fibromyalgia who helped set up the Valencia region’s pharmaceutical safety authority in the 1980s, said: “Metamizole continues to be dispensed without a prescription. It is prescribed in doses higher than those recommended, without taking into account the greater susceptibility of some people to suffer from agranulocytosis.”
He said he was concerned that adverse drug reactions were under-reported.
He added: “Do not prescribe it to patients from other countries where the drug has been withdrawn because of the increased risk of agranulocytosis associated with metamizole in those groups.”
He said the Spanish health authorities also needed to think about the intramuscular injections because of the reported risks of lesions, necrosis and sepsis.
Boehringer Ingelheim said: “Patient safety is our top priority, and we actively monitor the safety of our products on an ongoing basis and notify health authorities if new safety information becomes available.
“The side-effect of agranulocytosis is addressed in the current product information. The product is available on medical prescription only so that therapy is under supervision of a physician.”
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Patients sue Spanish government over banned painkiller