Loading...
Loading...
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Fluoroquinolone Antibacterial [EPC]
Levofloxacin is a potent, broad-spectrum fluoroquinolone antibiotic used to treat various bacterial infections by inhibiting essential bacterial enzymes. It is effective against respiratory, skin, and urinary tract infections.
Name
Levofloxacin
Raw Name
LEVOFLOXACIN
Category
Fluoroquinolone Antibacterial [EPC]
Drug Count
3
Variant Count
117
Last Verified
February 17, 2026
RxCUI
199885, 199884, 311296, 1665497, 1665507, 1665515, 477391, 1665517, 1665519, 314080, 545118
UNII
6GNT3Y5LMF
About Levofloxacin
Levofloxacin is a potent, broad-spectrum fluoroquinolone antibiotic used to treat various bacterial infections by inhibiting essential bacterial enzymes. It is effective against respiratory, skin, and urinary tract infections.
Detailed information about Levofloxacin
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Levofloxacin.
At the molecular level, levofloxacin exerts its bactericidal (bacteria-killing) effect by inhibiting two essential bacterial enzymes: DNA gyrase (topoisomerase II) and topoisomerase IV. These enzymes are critical for the process of DNA replication, transcription, repair, and recombination.
Because human cells use different types of topoisomerases that are structurally distinct from bacterial enzymes, levofloxacin shows high selectivity for bacterial targets, though it is not entirely without risk of off-target effects in human tissues, such as connective tissue and the central nervous system.
Understanding how the body processes levofloxacin is essential for optimizing therapeutic outcomes and minimizing toxicity.
Levofloxacin is FDA-approved for a wide array of bacterial infections. It is important to note that it should only be used for infections proven or strongly suspected to be caused by susceptible bacteria to prevent the development of drug-resistant organisms. Approved indications include:
Levofloxacin is manufactured in several forms to accommodate different clinical needs:
> Important: Only your healthcare provider can determine if Levofloxacin is right for your specific condition. Because of the risk of serious adverse reactions, the FDA recommends reserving fluoroquinolones for certain conditions (like sinusitis or uncomplicated UTI) only when no other options are available.
The dosage of levofloxacin depends entirely on the type and severity of the infection being treated, as well as the patient's kidney function. Typical adult dosages include:
Levofloxacin is generally not recommended for pediatric patients under the age of 18 due to an increased incidence of musculoskeletal disorders (arthralgia, arthritis, tendinopathy). However, it is FDA-approved for children 6 months of age and older specifically for:
For these specific conditions, dosing is weight-based:
Since levofloxacin is primarily eliminated by the kidneys, dosage adjustments are mandatory for patients with a Creatinine Clearance (CrCl) less than 50 mL/min. Failure to adjust the dose can lead to drug accumulation and toxicity. For example, if the standard dose is 750 mg, and the CrCl is between 20-49 mL/min, the dose may be reduced to 750 mg every 48 hours. Your doctor will monitor your kidney function (serum creatinine) to determine the appropriate schedule.
No dosage adjustment is typically required for patients with liver disease, as the drug is not significantly metabolized by the liver.
While no specific age-based dosage adjustment is required, elderly patients are more likely to have decreased kidney function and are at a higher risk for tendon rupture and QT prolongation. Dose selection should be cautious, often starting at the lower end of the dosing range.
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not double the dose to catch up, as this increases the risk of side effects.
Symptoms of a levofloxacin overdose may include severe dizziness, tremors, seizures, or hallucinations. In the event of an overdose, contact a poison control center or seek emergency medical attention immediately. Treatment is generally supportive, and the drug is not efficiently removed by hemodialysis.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance.
While levofloxacin is generally well-tolerated, some patients may experience mild to moderate side effects. These often resolve once the medication is discontinued:
> Warning: Stop taking Levofloxacin and call your doctor immediately if you experience any of these.
In some cases, the side effects of fluoroquinolones like levofloxacin can be long-lasting or permanent. This is sometimes referred to as Fluoroquinolone-Associated Disability (FQAD). It involves a constellation of symptoms affecting the joints, muscles, and nervous system that persist for weeks or months after the drug is stopped.
The FDA has issued its most serious warning (Black Box Warning) for levofloxacin because it is associated with disabling and potentially irreversible serious adverse reactions that may occur together, including:
Report any unusual symptoms to your healthcare provider.
Levofloxacin is a powerful antibiotic that carries significant risks. It should only be used for bacterial infections that cannot be treated with safer alternatives. Patients must be aware that the risk of serious side effects, such as tendon rupture or nerve damage, can occur even after just one or two doses. If you experience any new pain or neurological symptoms, stop the medication and contact your doctor immediately.
Levofloxacin carries a prominent FDA Black Box Warning regarding its association with disabling and potentially permanent side effects. These include tendinitis, tendon rupture, peripheral neuropathy (nerve pain or numbness), and central nervous system effects (such as anxiety, confusion, or seizures). Additionally, it is specifically contraindicated in patients with myasthenia gravis, as it can cause life-threatening respiratory muscle weakness.
While taking levofloxacin, your healthcare provider may require periodic monitoring, including:
Levofloxacin may cause dizziness, lightheadedness, or confusion. Do not drive, operate heavy machinery, or engage in activities requiring mental alertness until you know how the medication affects you.
While there is no direct chemical interaction between alcohol and levofloxacin, alcohol can worsen side effects like dizziness and nausea. Furthermore, alcohol can dehydrate the body and strain the immune system, potentially slowing your recovery from the infection.
Unlike some medications, levofloxacin does not require a tapering schedule. However, it is vital to complete the full course even if symptoms disappear. If the drug must be stopped due to a serious side effect, your doctor will switch you to a different class of antibiotic to ensure the infection is fully treated.
> Important: Discuss all your medical conditions with your healthcare provider before starting Levofloxacin.
Certain drugs should never be used with levofloxacin due to the risk of life-threatening complications:
For each major interaction, the mechanism usually involves either the inhibition of metabolic enzymes (like CYP1A2) or physical chelation in the digestive tract. The clinical consequence is either increased drug toxicity or a failure to treat the infection effectively.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.
Levofloxacin must NEVER be used in the following circumstances:
Conditions requiring a careful risk-benefit analysis by a healthcare professional include:
There is a high degree of cross-sensitivity among the fluoroquinolone class. If you are allergic to one (e.g., Cipro), you are highly likely to be allergic to Levofloxacin. There is no known cross-sensitivity between levofloxacin and other major antibiotic classes like penicillins, cephalosporins, or sulfonamides.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Levofloxacin.
Levofloxacin is classified as Pregnancy Category C. Data on the use of levofloxacin in pregnant women are limited and insufficient to inform a drug-associated risk of major birth defects or miscarriage. Animal studies have shown that fluoroquinolones can cause arthropathy (joint disease) in developing offspring. Consequently, levofloxacin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is generally avoided in the first trimester unless no other options exist for a life-threatening infection.
Levofloxacin is excreted in human breast milk. Because of the potential for serious adverse reactions in nursing infants (including the risk of damage to developing cartilage), a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. If a mother must take levofloxacin, some experts recommend pumping and discarding milk during treatment and for 48 hours after the last dose.
As previously noted, the safety and effectiveness of levofloxacin in pediatric patients are not established except for the management of inhalational anthrax and plague. The primary concern is the potential for permanent damage to weight-bearing joints. In clinical trials, pediatric patients treated with levofloxacin had a higher rate of musculoskeletal adverse events compared to those treated with other antibiotics.
Patients over the age of 65 are at a significantly higher risk for several severe side effects:
Levofloxacin clearance is substantially reduced in patients with impaired renal function (CrCl < 50 mL/min). Dosage adjustment is required to avoid toxicity. For patients on hemodialysis or continuous ambulatory peritoneal dialysis (CAPD), supplemental doses are not usually required after the procedure, as the drug is not easily removed.
Because levofloxacin is not significantly metabolized by the liver, its pharmacokinetics are not expected to be altered in patients with liver impairment. No specific dose adjustments are required for patients with cirrhosis or other liver diseases.
> Important: Special populations require individualized medical assessment.
Levofloxacin is the L-isomer of the racemate ofloxacin. Its antibacterial activity resides primarily in the L-isomer, which is 8 to 128 times more active than the D-isomer. It functions as a bactericidal agent by inhibiting the bacterial Type II topoisomerases: DNA gyrase and topoisomerase IV. By stabilizing the complex between the enzyme and the DNA, it prevents the ligation (rejoining) of DNA strands, leading to fragmented DNA and the cessation of bacterial protein synthesis and replication.
Levofloxacin exhibits concentration-dependent killing. The ratio of the Area Under the Curve (AUC) to the Minimum Inhibitory Concentration (MIC) is the primary predictor of clinical and microbiological success. It also possesses a post-antibiotic effect (PAE), meaning bacterial growth continues to be suppressed even after the drug concentration falls below the MIC.
| Parameter | Value |
|---|---|
| Bioavailability | 99% |
| Protein Binding | 24% - 38% |
| Half-life | 6 - 8 hours |
| Tmax | 1 - 2 hours |
| Metabolism | Minimal (<5% as metabolites) |
| Excretion | Renal 87%, Fecal <4% |
Levofloxacin is a member of the fluoroquinolone class. Other medications in this class include ciprofloxacin (Cipro), moxifloxacin (Avelox), and delafloxacin (Baxdela). It is specifically categorized as a "respiratory quinolone" because of its enhanced activity against Streptococcus pneumoniae compared to earlier quinolones.
Medications containing this ingredient
Common questions about Levofloxacin
Levofloxacin is a broad-spectrum antibiotic used to treat various bacterial infections, including pneumonia, sinusitis, and bronchitis. It is also effective for skin infections, chronic prostatitis, and certain types of urinary tract infections. In specialized cases, it is used to treat or prevent the plague and anthrax. Because it carries risks of serious side effects, healthcare providers often reserve it for infections that cannot be treated with other antibiotics. It is not effective against viral infections like the common cold or the flu.
The most common side effects reported by patients taking levofloxacin include nausea, diarrhea, headache, and dizziness. Some individuals may also experience insomnia or stomach pain. While these are often mild, they should be monitored closely. If diarrhea becomes severe or bloody, it could indicate a serious colon infection and requires immediate medical attention. Most mild side effects disappear shortly after the treatment course is completed.
There is no known direct interaction between alcohol and levofloxacin that makes the drug ineffective. However, alcohol can increase the severity of side effects such as dizziness, lightheadedness, and nausea. Alcohol also dehydrates the body, which can increase the risk of kidney irritation while taking this medication. To ensure the fastest recovery from your infection, it is generally recommended to avoid or limit alcohol consumption. Always consult your doctor about your lifestyle habits during antibiotic therapy.
Levofloxacin is generally not recommended during pregnancy unless the benefits significantly outweigh the potential risks to the fetus. It is classified as Category C, meaning animal studies have shown potential harm to developing joints and cartilage, but human data is lacking. Healthcare providers typically prefer safer alternatives, like penicillins or cephalosporins, for pregnant women. If you are pregnant or planning to become pregnant, you must discuss the risks with your doctor before starting this medication. Use in the first trimester is particularly scrutinized.
Most patients begin to feel an improvement in their symptoms within 48 to 72 hours of starting levofloxacin. However, the time it takes to fully clear the infection depends on the type and severity of the illness. For example, a simple urinary tract infection may resolve quickly, while chronic prostatitis requires 28 days of treatment. It is critical to finish the entire prescription even if you feel better within the first few days. Stopping early can lead to the return of the infection and the development of antibiotic-resistant bacteria.
You should not stop taking levofloxacin suddenly unless you experience a serious allergic reaction or a significant side effect like tendon pain or nerve tingling. If you stop the medication too early, the bacteria causing your infection may not be completely killed, allowing the infection to return. This also contributes to antibiotic resistance, making future infections harder to treat. If you feel the medication is causing intolerable side effects, contact your healthcare provider immediately. They will determine if you should switch to a different antibiotic.
If you miss a dose of levofloxacin, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed one and continue with your regular timing. Never take two doses at once to make up for a missed one, as this can increase the risk of toxicity and side effects. Maintaining a consistent level of the drug in your system is important for fighting the infection. Setting an alarm can help you remember to take it at the same time each day.
Weight gain is not a recognized or common side effect of levofloxacin. Most side effects associated with this medication are gastrointestinal, such as nausea or diarrhea, which are more likely to cause a temporary loss of appetite. If you notice sudden weight gain or swelling in your legs while taking this medication, it could be a sign of a different underlying issue, such as heart or kidney problems. You should report any unexplained swelling or rapid weight changes to your doctor immediately. Levofloxacin is generally considered weight-neutral.
Levofloxacin has several significant drug interactions that require caution. It should not be taken with antacids, iron supplements, or multivitamins containing zinc, as these prevent the antibiotic from being absorbed. It can also increase the effects of blood thinners like warfarin and certain heart rhythm medications. Taking it with steroids increases the risk of tendon rupture, and taking it with NSAIDs like ibuprofen may increase seizure risk. Always provide your doctor with a full list of all medications and supplements you are currently taking.
Yes, levofloxacin is widely available as a generic medication in tablet, oral solution, and intravenous forms. The brand name Levaquin was discontinued in the United States by its manufacturer, but the generic versions are FDA-approved and therapeutically equivalent. Generic levofloxacin is typically much more affordable than brand-name antibiotics. The availability of generic forms ensures that this important treatment remains accessible for patients with various bacterial infections. Check with your local pharmacy for pricing and availability.