Levofloxacin, sold under the brand name Levaquin among others, is a broad-spectrum antibiotic of the fluoroquinolone drug class. It is the left-handed isomer of the medication ofloxacin. It is used to treat a number of bacterial infections including acute bacterial sinusitis, pneumonia, H. pylori (in combination with other medications), urinary tract infections, Legionnaires' disease, chronic bacterial prostatitis, and some types of gastroenteritis. Along with other antibiotics it may be used to treat tuberculosis, meningitis, or pelvic inflammatory disease. It is available orally, intravenously, and in eye drop form.
Common side effects include nausea, diarrhea, and trouble sleeping. A warning concerning all fluoroquinolones was issued in 2016: "An FDA safety review has shown that fluoroquinolones when used systemically (i.e. tablets, capsules, and injectable) are associated with disabling and potentially permanent serious adverse effects that can occur together. These adverse effects can involve the tendons, muscles, joints, nerves, and central nervous system."
Other serious side effects may include tendon rupture, tendon inflammation, seizures, psychosis, and potentially permanent peripheral nerve damage. Tendon damage may appear months after treatment is completed. People may also sunburn more easily. In people with myasthenia gravis, muscle weakness and breathing problems may worsen. While use during pregnancy is not recommended, risk appears to be low. The use of other medications in this class appear to be safe while breastfeeding; however, the safety of levofloxacin is unclear.
Levofloxacin was patented in 1985 and approved for medical use in the United States in 1996. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2023, it was the 231st most commonly prescribed medication in the United States, with more than 1million prescriptions.
Medical uses Levofloxacin is used to treat infections including: respiratory tract infections, cellulitis, urinary tract infections, prostatitis, anthrax, endocarditis, meningitis, pelvic inflammatory disease, traveler's diarrhea, tuberculosis, and plague and is available orally, intravenously, and in eye drop form.
As of 2016, the US Food and Drug Administration (FDA) recommended that "serious side effects associated with fluoroquinolone antibacterial drugs generally outweigh the benefits for patients with acute sinusitis, acute bronchitis, and uncomplicated urinary tract infections who have other treatment options. For patients with these conditions, fluoroquinolones should be reserved for those who do not have alternative treatment options."
Levofloxacin is used for the treatment of pneumonia, urinary tract infections, and abdominal infections. As of 2007 the Infectious Disease Society of America (IDSA) and the American Thoracic Society recommended levofloxacin and other respiratory fluoroquinolines as first line treatment for community acquired pneumonia when co-morbidities such as heart, lung, or liver disease are present or when in-patient treatment is required. Levofloxacin also plays an important role in recommended treatment regimens for ventilator-associated and healthcare-associated pneumonia.
As of 2010 it was recommended by the IDSA as a first-line treatment option for catheter-associated urinary tract infections in adults. In combination with metronidazole it is recommended as one of several first-line treatment options for adult patients with community-acquired intra-abdominal infections of mild-to-moderate severity. The IDSA also recommends it in combination with rifampicin as a first-line treatment for prosthetic joint infections. The American Urological Association recommends levofloxacin as a first-line treatment to prevent bacterial prostatitis when the prostate is biopsied. and as of 2004 it was recommended to treat bacterial prostatitis by the NIH research network studying the condition.
Levofloxacin and other fluoroquinolones have also been widely used for the treatment of uncomplicated community-acquired respiratory and urinary tract infections, indications for which major medical societies generally recommend the use of older, narrower spectrum drugs to avoid fluoroquinolone resistance development. Due to its widespread use, common pathogens such as Escherichia coli and Klebsiella pneumoniae have developed resistance. In many countries as of 2013, resistance rates among healthcare-associated infections with these pathogens exceeded 20%.
Levofloxacin is also used as antibiotic eye drops to prevent bacterial infection. Usage of levofloxacin eye drops, along with an antibiotic injection of cefuroxime or penicillin during cataract surgery, has been found to lower the chance of developing endophthalmitis, compared to eye drops or injections alone.
Pregnancy and breastfeeding According to the FDA approved prescribing information, levofloxacin is pregnancy category C. This designation indicates that animal reproduction studies have shown adverse effects on the fetus and there are no adequate and well-controlled studies in humans, but the potential benefit to the mother may in some cases outweigh the risk to the fetus. Available data point to a low risk for the unborn child. Exposure to quinolones, including levofloxacin, during the first-trimester is not associated with an increased risk of stillbirths, premature births, birth defects, or low birth weight.
Levofloxacin does penetrate into breastmilk, though the concentration of levofloxacin in the breastfeeding infant is expected to be low. Due to potential risks to the baby, the manufacturer does not recommend that nursing mothers take levofloxacin. However, the risk appears to be very low, and levofloxacin can be used in breastfeeding mothers with proper monitoring of the infant, combined with delaying breastfeeding for 4–6 hours after taking levofloxacin.
Children Levofloxacin is not approved in most countries for the treatment of children except in unique and life-threatening infections because it is associated with an elevated risk of musculoskeletal injury in this population, a property it shares with other fluoroquinolones.
In the United States levofloxacin is approved for the treatment of anthrax and plague in children over six months of age.
Levofloxacin is recommended by the Pediatric Infectious Disease Society and the Infectious Disease Society of America as a first-line treatment for pediatric pneumonia caused by penicillin-resistant Streptococcus pneumoniae, and as a second-line agent for the treatment of penicillin-sensitive cases.
In one study, 1534 juvenile patients (age 6 months to 16 years) treated with levofloxacin as part of three efficacy trials were followed up to assess all musculoskeletal events occurring up to 12 months post-treatment. At 12 months follow-up the cumulative incidence of musculoskeletal adverse events was 3.4%, compared to 1.8% among 893 patients treated with other antibiotics. In the levafloxacin-treated group, approximately two-thirds of these musculoskeletal adverse events occurred in the first 60 days, 86% were mild, 17% were moderate, and all resolved without long-term sequelae.
Spectrum of activity Levofloxacin and later generation fluoroquinolones are collectively referred to as "respiratory quinolones" to distinguish them from earlier fluoroquinolones which exhibited modest activity toward the important respiratory pathogen Streptococcus pneumoniae.
The drug exhibits enhanced activity against the important respiratory pathogen Streptococcus pneumoniae relative to earlier fluoroquinolone derivatives like ciprofloxacin. For this reason, it is considered a "respiratory fluoroquinolone" along with more recently developed fluoroquinolones such as moxifloxacin and gemifloxacin. It is less active than ciprofloxacin against Gram-negative bacteria, especially Pseudomonas aeruginosa, and lacks the anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of moxifloxacin and gemifloxacin. Levofloxacin has shown moderate activity against anaerobes, and is about twice as potent as ofloxacin against Mycobacterium tuberculosis and other mycobacteria, including Mycobacterium avium complex.
Its spectrum of activity includes most strains of bacterial pathogens responsible for respiratory, urinary tract, gastrointestinal, and abdominal infections, including Gram negative (Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, Legionella pneumophila, Moraxella catarrhalis, Proteus mirabilis, and Pseudomonas aeruginosa), Gram positive (methicillin-sensitive but not methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Staphylococcus epidermidis, Enterococcus faecalis, and Streptococcus pyogenes), and atypical bacterial pathogens (Chlamydophila pneumoniae and Mycoplasma pneumoniae). Compared to earlier antibiotics of the fluoroquinoline class such as ciprofloxacin, levofloxacin exhibits greater activity towards Gram-positive bacteria but lesser activity toward Gram-negative bacteria, especially Pseudomonas aeruginosa.
Resistance Resistance to fluoroquinolones is common in staphylococcus and pseudomonas. Resistance occurs in multiple ways. One mechanism is by an alteration in topoisomerase IV enzyme. A double mutant form of S. pneumoniae Gyr A + Par C bearing Ser-81-->Phe and Ser-79-->Phe mutations were eight to sixteen times less responsive to ciprofloxacin.
Contraindications Package inserts mention that levofloxacin is to be avoided in patients with a known hypersensitivity to levofloxacin or other quinolones.
Like all fluoroquinolines, levofloxacin is contraindicated in patients with epilepsy or other seizure disorders, and in patients who have a history of quinolone-associated tendon rupture.
Levofloxacin may prolong the QT interval in some people, especially the elderly, and levofloxacin should not be used for people with a family history of long QT syndrome, or who have long QT, chronic low potassium, or are prescribed other drugs that prolong the QT interval.
A 2011 review examining musculoskeletal complications of fluoroquinolones proposed guidelines with respect to administration to athletes, that called for avoiding all use of fluoroquinolone antibiotics if possible, and if they are used: ensure there is informed consent about the musculoskeletal risks, and inform coaching staff; do not use any corticosteroids if fluoroquinolones are used; consider dietary supplements of magnesium and antioxidants during treatment; reduce training until the course of antibiotic is finished and then carefully increase back to normal; and monitor for six months after the course is finished, and stop all athletic activity if symptoms emerge.
Adverse effects Adverse effects are typically mild to moderate. However, severe, disabling, and potentially irreversible adverse effects sometimes occur, and for this reason it is recommended that use of fluoroquinolones be limited.