While everything from toothpaste to soap and certain medications have been linked to antibiotic resistance in the past, popular over-the-counter throat medication could be the latest health product causing antibiotic-resistant superbugs.
As countries in the Northern Hemisphere are just coming out of the cooler months, Australia is heading into the peak flu season where many people will use these medications to cure sore throats and other symptoms of cold and flu.
And now, new research presented at this year’s European Congress of Clinical Microbiology and Infectious Diseases in Amsterdam shows that the inappropriate use of antibiotics legally found in popular over-the-counter throat medications could be contributing to antibiotic resistance.
Researchers from the European Society of Clinical Microbiology and Infectious Diseases aimed to understand the development of bacterial resistance to four different antibiotics used in some over-the-counter throat medications including gramicidin, neomycin, bacitracin and tyrothricin.
Similarly, four species of bacteria with widespread antibiotic resistance including Staphylococcus aureus, Acinetobacter baumannii, Streptococcus pyogenes and Haemophilus influenza were examined. Researchers exposed species of bacteria to decreasing concentrations of antibiotics for 24 hours at human body temperature and bacteria that survived were then tested for antibiotic susceptibility.
Cross-resistance was also analysed to assess whether bacteria exposed to one antibiotic became susceptible to different antibiotics they hadn’t previously been exposed to. Researchers also checked whether in-use concentrations of antibiotics in over-the-counter medications were above the lowest concentration to still prevent bacterial growth, known as the minimum inhibitory concentration (MIC).
“We were concerned to find that some of the over-the-counter antibiotics used in sore throat preparations were not sufficiently concentrated to prevent growth of common human pathogens and are enabling these pathogens to develop resistance,” study author Adrian Shephard said in a statement.
“In addition, exposure to both standard and diluted concentrations of bacitracin was associated with clinical cross-resistance to other antibiotics.
“Our work raises doubt about the continued over-the-counter availability of these antibiotics for the treatment of sore throats, especially considering the primarily viral nature of the condition.”
Researchers said the study shows the potential of bacteria to adapt to chemotherapeutic antibiotics and the need to prudent or controlled use of antibiotics to be put in practice.
It follows a 2018 report by Public Health England that shows bloodstream infections have increased, with antibiotic-resistant bloodstream infections rising by 35 per cent between 2013 and 2017. Despite drug-resistant infections growing, 38 per cent of people in the United Kingdom still visit a GP to get antibiotics for coughs, throat, ear, sinus and chest infections.
Antibiotic resistance is particularly worrying for cancer patients with low immune systems, who rely on antibiotics to treat them. Antibiotics are essential in treating serious bacterial infections, but they’re commonly being used to treat illnesses including coughs, earaches and sore throats – which typically get better on their own. Public Health England says regular antibiotic use encourages harmful bacteria to become resistant, meaning the antibiotics don’t work as they’re meant to over time.