The commonly-prescribed antidepressant fluoxetine, which appears under the brand name Prozac, may be driving the antibiotic-resistance crisis, new research suggests.
When E.coli, which can cause food poisoning, is exposed to fluoxetine, the bacteria undergoes genetic mutations that stop it responding to common antibiotics, a study found. E.coli leads to life-threatening kidney damage in up to 10 per cent of cases.
According to the researchers, up to 11 per cent of fluoxetine passes through a person’s body unchanged before entering sewage systems via urine.
Experts have previously warned antibiotic resistance poses ‘as big a risk as terrorism’.
A lack of new drugs combined with overprescribing is thought to have driven the resistance crisis, which, according to the World Health Organization (WHO), ‘has the potential to affect anyone, of any age, in any country.’
The commonly-prescribed antidepressant fluoxetine, which appears under the brand name Prozac, may be driving the antibiotic-resistance crisis, new research suggests (stock)
The researchers, from the University of Queensland, exposed an E.coli strain to fluoxetine doses ranging from 0.5 to 100mg/L for 30 days in the lab.
This caused the bacteria’s genes to mutate, making the pathogen resistant to the commonly-prescribed antibiotics chloramphenicol, amoxicillin and tetracycline. These drugs are often used to treat skin, respiratory and urinary tract infections.
Results, published in the journal Environment International, further suggest the greater the fluoxetine dose E.coli is exposed to, the higher the rate of antibiotic resistance.
In addition, compared to bacteria that are not exposed to the antidepressant, those that spend 30 days with fluoxetine have up to 50 million times higher rates of resistance.
Fluoxetine is also prescribed under the brand names Prozep, Olena and Oxactin in the UK, and Rapiflux, Sarafem and Selfemra in the US.
Study author Jianhua Guo said: ‘Fluoxetine is a very persistent and well-documented drug in the wider environment, where strong environmental levels can induce multi-drug resistance.
‘This discovery provides strong evidence that fluoxetine directly causes multi-antibiotic resistance via genetic mutation.’
The researchers stress people should not stop taking their prescribed antidepressants but add their findings should be investigated to determine if such antibiotic resistance occurs outside of the lab.
Speaking of the resistance crisis, Professor Sean Brady, from The Rockefeller University, New York, previously said: ‘Despite the wide availability of antibiotics, infectious diseases remain a leading cause of death worldwide.
‘In the absence of new therapies, mortality rates due to untreatable infections are predicted to rise more than tenfold by 2050.’
The WHO has also classified antimicrobial resistance as a ‘serious threat’ to every region of the world.
Penicillin, the first and most famous antibiotic, was discovered by the Scottish microbiologist Alexander Fleming in 1928.
Fleming’s discovery allowed doctors to treat and cure infected patients, saving millions of lives.
Yet, less than a century after Fleming’s discovery, there are precious few antibiotics left and many superbugs are already resistant to all of them.
Figures suggest up to 50,000 people die each year due to antibiotic-resistant infections in Europe and the US alone.
Globally, at least 700,000 people pass away annually due to antibiotic-resistance complications from illnesses such as malaria, AIDS and tuberculosis.