The most widely prescribed antibiotics in the world are members of the quinolone family.

Cipro (ciprofloxin), Levaquin (levofloxacin) and Avelox (moxifloxacin) are the most common, used to treat respiratory ailments and urinary tract infections (UTIs). They are also the most known for adverse effects of antibiotics, like liver damage and one of the causes of  peripheral neuropathy.

Fluoroquinolones are among the most widely prescribed antibiotics in North America, falling into the ranks of those drugs that are over-prescribed. The number of adverse event reports on these drugs grows consistently, as do the warnings from health agencies.

The European Medicines Agency voiced concern about quinolones causing potential hepatotoxicity and Health Canada mentions the threat of liver damage. But one of the more dangerous risks is potentially permanent nerve damage, known as peripheral neuropathy or peripheral nerve damage.

Peripheral neuropathy is when the nerves that send information to and from the brain and spinal cord to the rest of the body get damaged. Impairment interferes with the connection, causing symptoms such as tingling, burning, numbness, or shooting pain in the arms and legs. The symptoms can also vary, depending on what nerves are impacted.

Causes of peripheral neuropathy, or peripheral nerve damage, can include alcoholism, autoimmune diseases, diabetes, and a host of other factors, such as effects of antibiotics. Fluoroquinolones fall into this list.

Posted as a quinolone side effect since 2004, peripheral nerve damage can be “long-lasting” and sometimes cause disability in fluoroquinolone takers. Reactions are such that the U.S. Food and Drug Administration (FDA) mandated updates to fluoroquinolone antibiotics warning labels in 2013 “to better describe the serious side effect of peripheral neuropathy.”

According to WebMD:

• Peripheral neuropathy symptoms typically begin rapidly, within a few days of starting the fluoroquinolones.
• Peripheral nerve damage symptoms may last for months or may even be permanent, despite stopping the drug.
• The risk for peripheral neuropathy appears to affect only those who take fluoroquinolones by mouth or by injection. Fluoroquinolones used in the eyes or ears are not linked to the risk.
• Contact your doctor immediately if you develop numbness, tingling, weakness, burning, shooting pains, or other symptoms while taking a fluoroquinolone.

The FDA also posted warnings about the side effects of antibiotics in this family in 2008, when they added a black box warning about the potential for tendon damage.

What are Fluoroquinolones?

A group of synthetic antibacterial drugs, fluoroquinolones are the only antibiotics that “directly inhibit bacterial DNA synthesis.” Quinolones were first discovered and used in 1962 in the form of nalidixic acid to treat UTIs. Fluoroquinolones were created when a fluorine atom was added.

It is noted that fluoroquinolones are meant to, and should be reserved to, treat bacterial infections. Usage guidelines from the Infectious Disease Society of America and other health organizations recommend minimizing the use of fluoroquinolones and other broad-spectrum antibiotics where not useful (like ear or sinus infections) to help prevent the development of superbugs.

The list of available drugs in this class has fallen over the years as several were taken off the market for potentially deadly adverse side effects. Today, six of them remain in use in the United States: levofloxacin (Levaquin), ciprofloxacin (Cipro), moxifloxacin (Avelox), norfloxacin (Noroxin), ofloxacin (Floxin), and gemifloxacin (Factive).

According to the FDA, “approximately 23.1 million unique patients received a dispensed prescription for an oral fluoroquinolone product from outpatient retail pharmacies during 2011.”

The risk for peripheral neuropathy occurs with this group, as oral or injected fluoroquinolones are alleged to be one of the causes of peripheral neuropathy.