What Is the Importance of Antimicrobial Susceptibility Testing for Off-Label Indications?

Jason Gallagher, PharmD, BCPS, FCCP, FIDSA, clinical professor of pharmacy practice, Temple University, explains the importance of antimicrobial susceptibility testing for off-label indications.

Interview Transcript (slightly modified for readability)

“When practitioners choose antibiotics, they aren’t necessarily choosing them based on the labeled indication that the drug has. [By this, I mean choosing an antibiotic based on] which organisms make it onto that label in the first place. For example, there may be 10 different organisms that can cause a urinary tract infection, and when a drug is first approved, it might be approved for 4 of them, even though it’s active against all 10. If that off-label susceptibility testing information is not available, then we don’t know if the drug is likely to work against those others.

It’s an issue that is fairly unique to infectious diseases because what the drug is first indicated for, may not be what practitioners ultimately end up using it for in times when there are few options available.”