A new study has documented the risk of nerve damage from taking powerful antibiotics in the class of fluoroquinolones. The best known of these drugs are Cipro (ciprofloxacin), Avelox (moxifloxacin) and Levaquin (levofloxacin).
The study, published in the September issue of the journal Neurology, found that current users of this class of antibiotics were at a higher risk of developing nerve damage, known as peripheral neuropathy, than non-users. The study further found that current new users of the drugs had the highest risk.
Oral fluoroquinolones are a strong class of antibiotics and one of the most often prescribed by doctors in the U.S. Last year, the FDA issued a warning regarding the risk of nerve damage from taking any oral doses of Cipro, Avelox, Levaquin, or others in this class of drugs. These risks came to light from adverse events reported from the FDA’s Adverse Event Reporting System and from published case reports. Absent still was any evidence from large epidemiologic studies that could establish a solid link between this drug and peripheral neuropathy.
The new study was the first to quantify the risk of nerve damage with the use of this class of drugs in older men. Because fluoroquinolones are often prescribed for diabetic patients with infections, who may be at a higher risk anyway of developing nerve damage, this study was able to exclude patients with diabetes. The study also excluded cases of peripheral neuropathy that were known to have a cause other than fluoroquinolones, such as hereditary peripheral neuropathy.
The study drew from a large sample size. It had access to the records of about one million men, ages 40 to 85, who were randomly selected from hospital files. Their treatments were tracked from 2001 – 2011. The researchers could see all data on drugs prescribed, hospitalizations, doctor visits, and demographic data.
The results showed that any use of a fluoroquinolone (FQ) was consistent with a 30% increase in the risk of peripheral neuropathy. The risk of peripheral neuropathy was highest for current new users of FQ. They found results for Cipro (ciprofloxacin), Avelox (moxifloxacin) and Levaquin (levofloxacin) were similar.
The researchers acknowledged that the results are “only directly generalizable to older men,” but also noted that almost half of the reported drug-related peripheral neuropathy (PN) cases occurred in this demographic. The researchers do not believe that the links would significantly differ in women.
The authors concluded: “The results of our study are consistent with an increase in the risk of PN with oral FQ use. In light of strong evidence of unnecessary prescribing of oral FQs in the United States, clinicians must weigh the risk of PN against the benefits of FQs when prescribing these drugs to their patient.”