Could older antibiotics help tackle drug resistance?
EU-funded researchers have analysed the efficacy and required dosage of several antibiotics licensed decades ago. Their findings could enable doctors to prescribe certain drugs with greater confidence and strengthen EU efforts to tackle the growing problem of drug resistance.
© pictoores #130993444, source: fotolia.com, 2018
Increasing antimicrobial resistance (AMR) is a worldwide health concern. Drugs are becoming obsolete, which puts patient lives at risk. In the EU alone, AMR is blamed for some 25 000 deaths annually and costs an estimated EUR 1.5 billion in healthcare expenses and lost productivity. Given that at present the supply of new antibiotics cannot keep up with demand, alternative effective medication needs to be found.
The EU-funded AIDA project sought to address this challenge by taking a closer look at older antibiotics to update what is known about them and determine if they could serve such a purpose. One solution is to rediscover older antibiotics in order to understand them better and identify possible new uses, says project coordinator Johan Mouton of the Erasmus University Medical Centre in the Netherlands. So many drugs that were licensed in the 50s, 60s and 70s have either disappeared off the market, or we do not know exactly how they work. Licensing requirements were different back then, so we have no real scientific studies that demonstrate the efficacy of these drugs.
Taking a closer look
AIDA researchers completed three clinical trials of five antibiotics that have not been in widespread use of late. The results, to be published over the next few years, will equip doctors with up to date information on a wider range of possible medication and ultimately improve treatments, according to Mouton.
The first to be looked at was colistin, which was licenced in the 1950s but subsequently abandoned. However, due to emerging resistance to newer antibiotics, colistin reappeared a decade ago as a treatment for severe infections.
The AIDA project investigated the efficacy of using colistin by itself or whether a combination of colistin and another drug might be more beneficial. From our findings, we have been able to recommend that doctors do not use combination therapy if this is not really necessary, says Mouton.
A second trial compared the effectiveness of the antibiotics nitrofurantoin and fosfomycin for treating lower urinary tract infections in women. A comparison of these drugs has never been done and little has been known about how these drugs actually work, says Mouton.
The third clinical trial compared rifampicin and minocycline with linezolid for treating skin infections.
In practice, the results will help doctors to decide on their first choice of antibiotic treatment, say Mouton. Furthermore, all our laboratory studies supported the outcomes of our clinical trials, which means we have been able to develop a solid framework for how these drugs can be used.
Although all clinical trials were performed in Europe, the AIDA project team was also in close contact with a National Institutes of Health (NIH) study group in the US that has been looking into the same issue.
Their trial design has been adapted to be able to combine our results, says Mouton. A combined analysis of these antibiotics will be much more powerful.