Medically Reviewed by Melinda Ratini, MS, DO on January 11, 2022
What Are Fluoroquinolones?

What Are Fluoroquinolones?


These antibiotics treat or prevent certain bacterial infections. You’re more likely to know them by their generic or brand names:

  • Ciprofloxacin (Cipro)
  • Delafloxacin (Baxdela)
  • Levofloxacin 
  • Moxifloxacin (Avelox)
  • Ofloxacin 

Doctors prescribe these as neded, but they can cause serious side effects. You should know what to look for when taking them.

Common Side Effects

Common Side Effects


Some people who took fluoroquinolones reported:

  • Nausea
  • Diarrhea
  • Headache
  • Dizziness
  • Lightheadedness
  • Trouble sleeping
Serious Physical Side Effects

Serious Physical Side Effects


There is a chance that your body will respond to these antibiotics with more severe reactions, including:

  • Tendinitis
  • Tendon rupture
  • Ruptures of the aorta
  • Numbness or tingling, “pins and needles” in arms and legs
  • Muscle weakness
  • Muscle pain
  • Joint pain
  • Joint swelling
  • Irregular heartbeat
  • Ringing or buzzing in ears
  • Vision problems
  • Skin rash
  • Skin sensitivity to sunlight
Serious Mental Side Effects

Serious Mental Side Effects


Some people have reported emotional and psychological reactions while taking these drugs, including:

  • Anxiety
  • Depression
  • Hallucinations
  • Suicidal thoughts
  • Confusion
When to Look for Changes

When to Look for Changes


Serious side effects can start after the first or second dose.

Most people who reported them had one or more of these:

  • Long-term pain
  • Problems with tendons, muscles, and joints, including swelling, pain, and tendon rupture
  • Symptoms that lasted  longer than a year, which means they may be permanent

These side effects led to changes in quality of life such as job loss, financial problems, and increased family tension.

Boxed Warning on Medication Label

Boxed Warning on Medication Label


The FDA put its strongest warning on the drug packaging.

You should know:

  • Fluoroquinolones carry a higher chance of tendinitis and tendon rupture.
  • It's greater for those over 60, in kidney, heart, and lung transplant recipients, and those taking steroid medications.
  • Stop taking the fluoroquinolone at the first sign of tendon pain, swelling, or inflammation. Avoid exercise and use of the affected area, and immediately ask your doctor to switch to a non-fluoroquinolone drug.

A higher incidence of ruptures or tears in the aorta has also been found with fluoroquinolones. Stop taking the medication if you have sudden severe constant pain in the stomach, chest or back. Seek medical treatment immediately.

Look for the Medication Guide

Look for the Medication Guide


Your prescription will come with FDA-approved information to help you recognize or avoid serious side effects.

Here’s part of the guide:

CIPRO ® (Sip-row) (ciprofloxacin hydrochloride) Tablets for oral use

Read this Medication Guide before you start taking CIPRO and each time you get a refill.  

There may be new information. This guide does not take the place of talking to your healthcare provider.

What is the most important information I should know about CIPRO?

  • CIPRO, a fluoroquinolone antibacterial medicine, can cause serious side effects.
  • Some of these serious side effects can happen at the same time and could result in death.

If you get any of the following serious side effects while you take CIPRO, you should stop taking CIPRO immediately and get medical help right away.

  • Joint pain, swelling, popping sounds, or muscle weakness
  • Tingling and possible nerve damage
  • Anxiety, depression, hallucinations, suicidal thoughts, confusion
Benefits vs. Risks

Benefits vs. Risks


For some types of sinusitis, chronic bronchitis, and urinary tract infections, the risks of fluoroquinolone drugs are greater than the benefits for most people.

For some serious infections, like pneumonia or infections inside the abdomen, the benefits of fluoroquinolone drugs outweigh the risks.

Your health care provider can talk to you about your best choice.

What Do You Need to Do?

What Do You Need to Do?


Before you take a fluoroquinolone, read the entire Medication Guide to understand warnings and side effects.

Stop taking Cipro and seek emergency medical help right away if you have any serious side effects after starting treatment, such as:

  • Unusual joint or tendon pain
  • Muscle weakness
  • A tingling or burning sensation
  • Arm or leg numbness
  • Pain in the abdomen, chest or back
  • Confusion and hallucinations

Report any side effects to your health care professional and the FDA MedWatch program.

FDA MedWatch Program

FDA MedWatch Program


You can report a bad side effect to the FDA in these ways:

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U.S. Food and Drug Administration.