An over-the-counter drug used to treat diarrhea combined with minocycline, an
antibiotic used to treat bacterial infections, could one day change the lives of those
living with cystic fibrosis.

Researchers at McMaster University have discovered this creative approach to
tackle
antibiotic resistance to bacterial infections, a frequent complication of those with cystic
fibrosis. Cystic fibrosis is the most common, fatal genetic disease affecting Canadian
children and young adults.

“Antibiotic resistance is having a profound effect on known drugs that are used to
treat
illness and disease,” said researcher Eric Brown, professor and chair of McMaster's
Department of Biochemistry and Biomedical Sciences and member of the Michael G.
DeGroote Institute for Infectious Disease Research (IIDR).

“Previous advances in treating cystic fibrosis have been in managing infection, but
since infectious organisms are increasingly developing resistance to antibiotics, the
importance of providing new treatments is more important than ever.”

Brown, who made the discovery in collaboration with McMaster researchers Gerry
Wright and Brian Coombes, found that the combination of these two drugs inhibits the
growth of bacteria after screening a collection of previously approved non-antibiotic
drugs within McMaster's Centre for Microbial Chemical Biology.

Their screening revealed that this particular combination using the anti-diarrhea
drug
loperamide increases the efficacy of the antibiotic minocycline against multidrug
resistant P. aeruginosa.

“Typically it takes 13 to 15 years to develop a drug,” says Brown. “We think that
this
approach could cut drug development time in half.”

“These exciting research findings hold promise that a new, safer method for
treating
devastating lung infections in people with cystic fibrosis may be just around the
corner,” said Maureen Adamson, CEO of Cystic Fibrosis Canada, a charity that partnered
with the Canadian Institutes of Health Research to fund the project. “These findings
could impact healthcare worldwide as antibiotic resistance is a tremendous threat to
many populations.”

Wright, scientific director of the IIDR, adds that McMaster is one of the only
universities
to look at the combination of antibiotic and non-antibiotic drugs in combating
bacterial resistance. But he believes this marks the beginning of using combination
therapy as a more effective way to treat disease.

“This finding has opened doors to discovering the abilities of drugs when
combined,”
he says. “Not only has antibiotic resistance become a growing threat to managing
illness and disease, the use of combination therapy has added benefits. These
combinations might be a way to selectively target bacteria and combat disease and
leave so-called “good bacteria” intact to do other things. In effect you use fewer
antibiotics to get the same effect.”