Õ¬Äе¼º½

Many pills of different colours scattered all over a surface
Image: iStock
1 February 2023

University of Queensland researchers have found a range of commonly prescribed antidepressants can increase bacteria’s resistance to antibiotic medications.

A study led by  from Õ¬Äе¼º½’s  focused on prescription drugs used to treat depressive disorders, anxiety disorders, and other psychological conditions.

More than 42 million prescriptions were dispensed for antidepressant medications in Australia in 2021 and the study investigated bacterial exposure to five of the most common drugs - sertraline (Zoloft), escitalopram (Lexapro), bupropion (Welbutrin), duloxetine (Cymbalta) and agomelatine (Valdoxan). 

Two scientists wearing lab coats in a science laboratory. They are both smiling.“While the overuse of antibiotics is acknowledged as the major driver of bacterial resistance, we wanted to investigate if other common medications were contributing to the problem,” Professor Guo said. 

“Sertraline, duloxetine and fluoxetine had the strongest impact on bacterial resistance to antibiotics among the drugs we tested.

“Our study showed a marked increase in antibiotic resistance from those three, even at very low doses.

“Notably, the antibiotic resistance appears to be antidepressant-dependent, which may be due to oxidative stress in bacteria posed by antidepressants.

“Further studies need to evaluate the potential effects on the microbiomes of people given antidepressants and assess their risk gastrointestinal disturbances or diseases.”

It is estimated 1.27 million people die every year from infections which do not respond to medication and the figure is  by 2050 unless global action is taken.

The study was published in  and was funded by the , and the Õ¬Äе¼º½ Foundation Research Excellence Awards.

Image: Dr Yue Wang (left) and Professor Jianhua Guo (right)

Media: Professor Jianhua Guo, jianhua.guo@uq.edu.au, +61 7 3346 3222, +61 426 668 158; Sharon James, Australian Centre for Water and Environmental Biotechnology, sharon.james@uq.edu.au, +61 404 624 773.