Trifluoperazine, doxapram, and amoxapine effectively treated antibiotic-resistant Yersinia pestis.
A recent study found that non-antibiotic therapeutic drugs could potentially be effective in fighting antibiotic-resistant pathogens.
According to a study published by the Journal of Antimicrobial Agents and Chemotherapy, antibiotic resistance is on the rise largely due to the overprescribing of antibiotics.
"There are no new antibiotics which are being developed and nobody really has given much emphasis to this because everyone feels we have enough antibiotics in the market," said study author Ashok Chopra, CSc, PhD. "But now the problem is that bugs are becoming resistant to multiple antibiotics. That's why we started thinking about looking at other molecules that could have some effect in killing such antibiotic resistant bacteria."
Researchers screened 780 FDA-approved therapeutics and were able to identify 94 drugs that were effective in a cell-culture system when tested against Yersinia pestis, which is the bacteria that caused the plague and is now becoming antibiotic resistant.
Researchers found that 3 drugs, trifluoperazine, an antipsychotic; doxapram, a breathing stimulant; and amoxapine, an anti-depressant; effectively treated plague bacteria in mouse models.
According to the study, trifluoperazine successfully treated Salmonella enterica and Clostridium difficile infections, which are considered drug-resistant bacteria of serious threat by the CDC.
"It is quite possible these drugs are already, unknowingly, treating infections when prescribed for other reasons," Dr. Chopra said.
Researchers said these drugs could be affecting the virulence of the bacteria, or are working through the host, and could affect host proteins or genes so the bacteria cannot use them to grow.
The authors noted that further studies are needed in order to determine the exact reasoning behind the effects of these drugs.
"This area of antibiotic resistance is a big problem in global terms. That's why we started thinking of what different ways we can use drugs already available to combat this problem,” Dr. Chopra concluded.