Antibiotic resistance is one of the biggest threats to global health, food security and development, says the World Health Organization (WHO). It can affect anyone and is a natural phenomenon, although the misuse of these medications in humans and animals is accelerating the process.
This resistance occurs when bacteria mutate in response to antibiotics, used to prevent and treat bacterial infections. Thus, the loss of effectiveness of these drugs makes it difficult to treat more and more common infectious diseases, prolonging hospital stays and increasing medical costs and mortality.
It is estimated that around 35,000 people die each year in Europe as a result of resistant infections, of which 4,000 in Spain, and health professionals are working hard to find alternatives. The development of new medications is the most effective way, but sometimes old drugs have also been recovered due to the loss of effectiveness of current antibiotics. And the results are not always positive.
Researchers at the Hospital del Mar, in Barcelona, have shown that increasing the dose of colistin – an antibiotic that began to be used in the 1950s and had fallen into disuse – to treat pneumonia caused by a certain bacteria (Pseudomonas aeruginosa) resistant to Medications are not only not useful in treating the infection but can cause increased mortality among patients.
Professionals began to detect the presence of this multi-resistant bacteria in the hospital around 2005 and had to resort to the old antibiotic, which had stopped being administered due to its contraindications and harm, due to the lack of response from other medications. For eight years (2010-2018) they studied the effects of the revival.
The conclusion, now published in the journal Microbiology Spectrum, is that in high doses colistin can be toxic to the kidneys. “We have seen that, even if it did not cause toxicity, with high levels of colistin we did not solve anything,” explains Lluïsa Sorlí, principal investigator of the study.
The work has made it possible to adjust the doses of the antibiotic to improve patient safety, which has implied a change in administration. The intravenous route has been abandoned in favor of nebulization, so that a better concentration of the drug is achieved in the lungs, where the infection resides, without passing through the blood, thus avoiding affecting the kidneys.
According to Sorlí, in our environment there are now more therapeutic options to treat infection caused by Pseudomonas aureginosa, which represents 36% of cases of pneumonia associated with the need for mechanical ventilation in Spain, Italy and Greece. “But in other parts of the world and in places with high rates of resistance, colistin continues to be used as an alternative.”
The incidence maps of multi-resistant microorganisms in southern Europe are alarming, the doctor warns, and although they are located mainly inside hospitals, and more specifically in the services where the most serious cases are treated, they are increasingly being detected. greater presence in the community.