Two common antibiotics may be causing some serious harm to senior citizens. Researchers are claiming that antibiotics commonly used for respiratory, sinus and other bacterial infections may boost the risk of severe liver injury in seniors.
A new study found that commonly prescribed “fluoroquinolone” antibiotics, moxifloxacin (Avelox) and levofloxacin (Levaquin), doubled the likelihood of admission to hospital for acute liver injury compared to other antibiotics like clarithromycin.
(MORE: Injury Profile: Liver Damage)
European Medicines Agency and Health Canada Already Warn
While regulators like the European Medicines Agency and Health Canada have issued warnings about the risk of liver injury from moxifloxacin, there is little research on the safety of fluoroquinolones, especially related to liver damage.
Researchers assessed the risk of acute liver injury in patients taking moxifloxacin compared with those taking other antibiotics used to treat respiratory tract infections.
Canadian researchers examined 9 years of medical records of 144 patients in Ontario who were over 65 and admitted to the hospital to treat liver injury within a month of receiving fluoroquinolones. The patients had no history of liver disease, and 88 of them died.
Researchers excluded patients who had been admitted for previous liver disease or recent hospitalization.
“Compared with clarithromycin, moxifloxacin was associated with a more than twofold increased risk of admission to hospital for acute liver injury,” the study authors wrote in a journal news release. “Levofloxacin was also associated with a statistically significant but lower risk of hepatotoxicity than moxifloxacin.”
However, the risk of liver injury is rare, say the researchers, from Toronto’s Institute for Clinical Evaluative Sciences, the University of Toronto and McMaster University in Hamilton, Ontario. Liver problems affect about six of each 100,000 patients treated with the antibiotics, they found.
“Despite recent regulatory warnings regarding the hepatic safety of moxifloxacin, there is a lack of controlled studies supporting the notion that moxifloxacin presents a particular risk relative to other broad-spectrum antibiotic agents and, in particular, to other fluoroquinolones,” the authors said.
While the study found an association between use of these antibiotics and liver injury, it does not show a cause-and-effect relationship.
“Although our results require confirmation in other settings, they suggest that both [Avelox (moxifloxacin)] and [Levaquin (levofloxacin)] be considered for regulatory warnings regarding acute liver injury,” the authors wrote….
They acknowledged that the study was limited by the use of administrative data, and lack of information on liver function, actual medication use, use of nonprescription drugs, or cause of death. They also could not control for genetic susceptibility to liver injury. Finally, the inclusion of patients 66 and older who were admitted to the hospital only, which precludes conclusions about younger patients and those with less severe liver injury.
Nonetheless, “our findings make an important contribution to an evidence base that is currently limited to case reports and registries of drug-induced liver injury,” they said.
You can find this published study in CMAJ (the Canadian Medical Association Journal.) dated Aug. 13.