Banned in the UK and Sweden, Nolotil, a pain reliever whose main component is Metamizol, is commonly prescribed in Portugal and Spain.
In August, Spain’s drugs and sanitary products regulator AEMPS was reported by The Times to have “confirmed it had launched an investigation into concerns that northern Europeans may be more at risk of side effects” than others.
The AEMPS also updated the metamizol datasheet in light of the investigation, and issued a recommendation that the drug be taken responsibly, “for short-term treatments, sold with a prescription, and before it is issued, detailed blood tests should be performed in order to avoid risk factors for agranulocytosis”.
Another recommendation refers to the non-use of metamizole in patients “in whom it is not possible to perform controls”, such as “fluctuating populations”, interpreted by some as a ban on prescribing the drug to tourists.
Its manufacturer, Boehringer Ingelheim, denied a ban, saying it was merely “reinforcement that it should only be used with a prescription”.
The AEMPS’ investigation came after Spanish medical translator Cristina Garcia del Campo lobbied for a probe after discovering a link between blood poisoning in several British and Irish tourists and the drug.
The Times also said that over “100 British and Irish expatriates and holidaymakers in Spain have suffered devastating side effects after taking the drug”, such as blood poisoning and amputations.
On Wednesday, Portugal’s drugs watchdog Infarmed issued a bulletin on its website that recommended care in the use of medicines such as Nolotil.
In Portugal, medicines sold containing metamizole are Nolotil, Dolocalma and Metamizol Cinfa.
Nolotil is prescribed for acute and severe pain, including spasmodic pain and tumour pain, and high fever, which does not respond to other antipyretic treatment. It is available over-the-counter in Mexico, India, Brazil, Russia, but is banned in the US, Sweden, Japan, Australia and much of Europe.
Addressing the recent reports, Infarmed stressed that “Metamizole has been used for the treatment of pain and fever for about 40 years” in Portugal, and acknowledged “the use of medications containing this substance may cause an adverse reaction - agranulocytosis - which, although severe, is very rare”.
Agranulocytosis is an acute condition involving a severe and dangerous drop in the white blood cell count.
Infarmed said that in Portugal, a total of 11 cases of agranulocytosis potentially associated with the use of metamizole were reported to the pharmaco-vigilance system between 2008 and 2018, “with a frequency of 1 to 2 cases per year (which is within the expected frequency of one very rare reaction)”.
It did not specify how many, if any, of those cases were foreign nationals, namely Britons or northern Europeans.
To minimize the risk of agranulocytosis associated with the use of metamizole, Infarmed recommends its use is restricted to “a maximum of 7 days”, and in the case of longer use, “the blood count values should be monitored”.
Among other recommendations, it also advised particular attention to the prescription of such medicinal products in elderly patients, and advised prescribing physicians and other health professionals to “pay particular attention to the prevention and / or early detection of this or other undesirable effects”.
Despite the recent scare surrounding the drug, Infarmed noted that “these medicinal products maintain a positive risk-benefit relationship, provided that all conditions, including the indications for use of metamizole and the above precautions (listed in the SPC and FI of this medicinal product) are met.”
Infarmed concluded by saying it will “continue to monitor and disseminate all relevant information on this subject in coordination with the other partners and with the European Medicines Agency”.
A report in Portuguese newspaper Observador has meanwhile recalled that “in 2009, a Spanish study had already warned of the danger of Britons being medicated with Nolotil”.
It said the study, conducted by researchers at the Internal Medicine Unit of the Costa del Sol Hospital in Marbella and published in the Revista Clínica Española, titled ‘Agranulocytosis from Metamizole: A Potential Problem for the British’, had concluded that in Spain, “agranulocytosis from metamizole is an adverse effect that occurs more frequently in the British, therefore its use should be avoided”.
In a recent statement, manufacturers Boehringer Ingelheim said there is “no scientific evidence” Nolotil causes the side effects mentioned in relation to “genetic peculiarities”, meaning specific populations are not affected, but added it “regrets the deaths and will continue to monitor and evaluate, in collaboration with health authorities, any safety issues potentially associated with their medicines”.
Infarmed stressed that patients who have been prescribed metamizole “should not discontinue treatment”.
It said a doctor should be seen immediately “if there are signs and symptoms of blood dyscrasia, such as general malaise, infection, persistent fever, bruising, bleeding or paleness”.