Levofloxacin is a prescription antibiotic used to treat a range of bacterial infections, from pneumonia and sinus infections to urinary tract infections and skin infections. Sold under the brand name Levaquin, it belongs to a class of antibiotics called fluoroquinolones and is typically reserved for infections that are moderate to severe or haven’t responded to other treatments.
Infections Levofloxacin Treats
Levofloxacin is FDA-approved to treat the following bacterial infections in adults:
- Pneumonia: both community-acquired pneumonia (the kind you pick up in daily life) and nosocomial pneumonia (infections acquired in a hospital setting)
- Complicated and uncomplicated urinary tract infections
- Acute kidney infections (pyelonephritis)
- Chronic bacterial prostatitis
- Skin infections: both complicated cases involving deeper tissue and straightforward surface infections
- Acute bacterial sinusitis
- Acute bacterial flare-ups of chronic bronchitis
- Anthrax (post-exposure, inhalational)
- Plague
For anthrax and plague, levofloxacin is also approved for use in children. For all other indications, it’s approved only for adults 18 and older.
One important distinction: the FDA specifically notes that for uncomplicated UTIs, sinus infections, and bronchitis flare-ups, levofloxacin should only be used when no other antibiotic options are available. These are generally milder infections where the risks of a fluoroquinolone may outweigh the benefits. For more serious infections like pneumonia or complicated UTIs, levofloxacin remains a first-line or second-line choice.
How It Works
Levofloxacin kills bacteria by interfering with their ability to copy and repair DNA. Specifically, it blocks two essential enzymes that bacteria need to unwind and replicate their genetic material. Without these enzymes functioning, the bacterial DNA breaks apart and the cell dies. This mechanism makes levofloxacin effective against a broad range of bacteria, including both gram-negative organisms (like those causing UTIs) and gram-positive organisms (like those behind many pneumonias and skin infections).
Treatment Duration
How long you take levofloxacin depends entirely on the infection being treated. Community-acquired pneumonia typically requires 5 to 14 days of treatment. Complicated skin infections run 7 to 14 days, while uncomplicated skin infections take 7 to 10 days. Sinus infections may be treated with a course as short as 5 days or as long as 14 days. The medication is taken once daily, which is more convenient than antibiotics that require multiple doses throughout the day.
Common Side Effects
Diarrhea is the most frequently reported side effect. Nausea, headache, and dizziness also occur in some people. These are generally mild and resolve after the course of treatment ends.
Less common but more concerning side effects include severe or bloody diarrhea (which can signal a secondary gut infection), skin rashes, confusion, agitation, and hallucinations. Mental health changes like these can appear after just one dose.
Serious Risks to Know About
Levofloxacin carries an FDA black box warning, the most serious type of safety alert, for three categories of harm: tendon damage, nerve damage, and central nervous system effects.
Tendon Problems
Fluoroquinolones increase the risk of tendinitis and tendon rupture. The Achilles tendon is the most commonly affected, and a rupture there can require surgery. Tendons in the shoulder, hand, biceps, and thumb have also been reported as affected. The risk is highest in people over 60, those taking corticosteroids, and organ transplant recipients. Strenuous physical activity, kidney problems, and conditions like rheumatoid arthritis further raise the risk. Tendon rupture can happen while you’re taking the drug or months after finishing it.
Nerve Damage
Levofloxacin can cause peripheral neuropathy, a type of nerve damage that produces pain, burning, tingling, numbness, or weakness in the hands and feet. This is rare, but it can become permanent if the medication isn’t stopped promptly when symptoms appear.
Central Nervous System Effects
Some people experience seizures, tremors, restlessness, anxiety, confusion, hallucinations, paranoia, depression, nightmares, or insomnia. In rare cases, suicidal thoughts have been reported. People with a history of seizures or brain-related conditions face higher risk. These reactions can start after a single dose.
What Interferes With Levofloxacin
Minerals like calcium, magnesium, iron, and aluminum (found in many antacids and supplements) bind to levofloxacin in the gut and prevent your body from absorbing the full dose. The standard recommendation is to take levofloxacin at least two hours before or two hours after any product containing these minerals. Research in cystic fibrosis patients showed that even with two hours of spacing, calcium supplements reduced peak blood levels of levofloxacin by about 19%, suggesting that separating doses as much as possible improves absorption.
This interaction matters because a reduced dose reaching your bloodstream doesn’t just make the antibiotic less effective for you. It also creates conditions where bacteria are more likely to develop resistance.
Who Should Not Take It
Levofloxacin is contraindicated in anyone with a known hypersensitivity to it or other fluoroquinolones. Because of the tendon, nerve, and CNS risks, it’s generally avoided in people over 60 who are also on corticosteroids, organ transplant recipients, and those with a history of tendon disorders. People with epilepsy or other seizure conditions face elevated risk from the central nervous system effects. Outside of anthrax and plague, it is not approved for children, primarily because fluoroquinolones have shown potential to damage developing cartilage and joints in animal studies.