Levofloxacin — Compare Prices at US & Canada Pharmacies

• Levofloxacin is a fluoroquinolone antibiotic prescribed to treat bacterial infections of the lungs, urinary tract, kidneys, sinuses, and skin, but does not work against viruses.
• This antibiotic functions by blocking bacterial enzymes required for growth and is available in oral, intravenous, and ophthalmic forms.
• Serious adverse effects including tendonitis, tendon rupture, peripheral nerve damage, seizures, heart rhythm disturbances, and liver damage are possible, requiring careful medical supervision.
• Alternative antibiotics such as ciprofloxacin, moxifloxacin, sulfamethoxazole/trimethoprim, azithromycin, and cephalexin may be prescribed depending on the infection type and patient factors.

Certain bacterial infections affecting the lungs, kidneys, or sinuses may be treated with levofloxacin, an antibiotic that physicians frequently prescribe when appropriate. Bacteria vary considerably in type and behavior, triggering illnesses ranging from mild to severe. Levofloxacin works against many bacterial strains across multiple body systems, making it a valuable tool in a clinician's antibiotic arsenal. However, this medication requires careful consideration. It carries potential drug interactions and can produce serious adverse effects. This guide explores levofloxacin's mechanism, approved uses, possible side effects, and what patients should know before starting treatment.

Levofloxacin is a fluoroquinolone-class antibiotic that treats bacterial infections across various organ systems, including pneumonia, sinusitis, bronchitis, and prostatitis. The drug is available as a generic prescription medication in multiple formulations. "Healthcare providers might use oral, intravenous, or ophthalmic formulations to treat bacterial infections of multiple different organ systems," according to Justin Friedlander, MD, a urologist for the Einstein Healthcare Network.

As a fluoroquinolone, levofloxacin works by inhibiting enzymes bacteria need to survive and replicate. Levaquin was the brand-name version manufactured by Janssen Pharmaceuticals, though it was discontinued in 2017. The medication is ineffective against viruses, so it cannot treat viral illnesses like the common cold, influenza, or COVID-19.

Because levofloxacin can cause potentially severe side effects, it is available only by prescription. This requirement allows healthcare providers to determine whether the benefits outweigh risks in each patient's specific situation.

Levofloxacin demonstrates efficacy against numerous bacterial species, including E. coli, S. aureus, and S. pneumoniae. It is classified as a respiratory fluoroquinolone because of its strong activity against S. pneumoniae, a pathogen that infects the lungs and respiratory tract. Moxifloxacin and gemifloxacin share this classification.

Physicians commonly prescribe levofloxacin for acute exacerbation of chronic bronchitis, bacterial pneumonia, complicated and uncomplicated urinary tract infections, kidney infections (pyelonephritis), prostate infections, skin infections, and sinus infections. It is also FDA-approved for plague, post-exposure anthrax prophylaxis, and bacterial eye infections. Research has shown effectiveness against certain sexually transmitted diseases, particularly chlamydia.

Given the serious risks associated with levofloxacin, it should be reserved for conditions like sinusitis, bronchitis, and uncomplicated urinary tract infections when no suitable alternative treatments are available.

Levofloxacin can produce side effects ranging from common to potentially severe. Most patients who follow their physician's guidance and report concerns promptly do not experience serious complications. The most frequently reported side effects include nausea, diarrhea, constipation, headache, dizziness, and insomnia. While these align with side effect profiles of many medications, levofloxacin has drawn scrutiny in recent years for rare but serious adverse effects.

Levofloxacin use has been associated with tendonitis and tendon rupture. Patients may experience bruising, tearing, and impaired movement in the affected tendon. The Achilles tendon at the back of the ankle is most commonly involved, though the shoulder, hands, and other tendons can be affected. Risk factors include age over 60, concurrent corticosteroid use, and prior kidney, lung, or heart transplantation.

Peripheral neuropathy represents another serious risk, causing pain, weakness, burning, tingling, or numbness in the arms, legs, hands, and feet. Central nervous system effects—including seizures, lightheadedness, tremors, confusion, hallucinations, and severe headaches—are possible.

Cardiac complications such as QT prolongation and torsades de pointes may develop, manifesting as rapid or irregular heartbeats. Photosensitivity can occur, resulting in severe sunburn, blistering, and rashes from brief sun exposure. Liver injury may present with dark urine, vomiting, abdominal pain, pale stools, and jaundice.

Patients with myasthenia gravis may experience worsening muscle weakness, eyelid drooping, swallowing difficulties, and blurred or double vision. Allergic reactions ranging from rash and hives to anaphylaxis have been reported. Additional serious effects include aortic aneurysms, bacterial colitis, joint problems, and blood sugar dysregulation.

According to Dr. Friedlander, "side effects can occur hours to weeks after exposure and may potentially be permanent," citing a 2016 FDA warning. Although these serious effects are uncommon, patients with pre-existing medical conditions—particularly heart, joint, or metabolic disorders—should discuss their individual risk profile with their healthcare provider before starting treatment.

Standard levofloxacin dosing is 250, 500, or 750 mg once daily for 5 to 10 days. The drug can be given to adults and children weighing at least 30 kg (approximately 66 pounds) with normal kidney function. Actual doses vary based on the type and severity of infection, route of administration, patient age and weight, and concurrent medications.

Although levofloxacin often produces symptom improvement within several days, patients should complete the full antibiotic course exactly as prescribed, even if they feel better sooner. Stopping early may allow bacteria to survive and develop resistance.

The following table shows FDA-recommended dosing for adults with normal renal function:

Pregnant women and those who are breastfeeding should consult their healthcare provider before taking levofloxacin. Adequate controlled trials in pregnant women are lacking. Because levofloxacin enters breast milk, nursing mothers may consider expressing and discarding milk during treatment and for two days after the final dose to minimize infant exposure.

Older adults (age 65 and above) may take levofloxacin, though reduced kidney function may prolong drug clearance. Physicians often adjust dosing for elderly patients, who face increased risks of cardiac, hepatic, and tendon complications. Levofloxacin is not FDA-approved for children under 18 years except in cases of inhalational anthrax or plague exposure due to potential adverse effects and is contraindicated in children weighing less than 30 kg.

Levofloxacin can interact significantly with other medications and substances. The following combinations should be avoided or carefully timed:

Antacids, mineral supplements containing iron, magnesium, zinc, or aluminum, multivitamins, and sucralfate reduce levofloxacin absorption. These should be taken at least two hours before or after levofloxacin doses.

Didanosine (an HIV medication) similarly impairs gastrointestinal absorption and requires the same two-hour separation.

Warfarin's anticoagulant effects may be increased by levofloxacin, raising bleeding risk. Blood clotting parameters may require closer monitoring.

Antidiabetic medications, including metformin, carry an increased risk of blood sugar fluctuations when combined with levofloxacin. Glucose monitoring may be necessary during and after treatment.

Nonsteroidal anti-inflammatory drugs like ibuprofen or aspirin may heighten central nervous system side effects, particularly seizure risk.

Patients should inform their prescriber of all medications, supplements, and over-the-counter products they use, as other interactions are possible.

Janssen Pharmaceuticals discontinued Levaquin (levofloxacin) and Floxin Otic (ofloxacin ear drops) in December 2017. The company cited broad availability of alternative antibiotics as the reason. However, the discontinuation followed multiple lawsuits from patients who experienced severe complications including aortic aneurysms and tendon ruptures. Plaintiffs alleged that Janssen marketed the drug despite known dangerous side effects.

Prior to these legal actions, the FDA had issued a black box warning—its most severe cautionary label—for serious adverse effects linked to Levaquin, Cipro, Avelox, and other fluoroquinolones. The generic formulation of levofloxacin remains widely prescribed and available.

Although the Levaquin brand was discontinued, levofloxacin's generic form remains available and prescribed. Physicians have several alternative antibiotics to consider for similar bacterial infections.

Ciprofloxacin (Cipro) is among the most common alternatives. Both are fluoroquinolones treating overlapping infection spectra and share similar adverse effect profiles. Cipro is also used for typhoid fever and some gonorrhea strains.

Moxifloxacin (Avelox) is another fluoroquinolone with a similar range of activity. Both drugs treat various bacterial infections, and moxifloxacin is available in generic form.

Sulfamethoxazole/trimethoprim (Bactrim) treats ear infections, urinary tract infections, traveler's diarrhea, bronchitis, and certain pneumonias. It is comparably effective to levofloxacin for some infections but does not carry tendonitis risk. However, it may cause severe skin reactions and is contraindicated in patients with sulfa allergies.

Azithromycin (Zithromax, Z-Pak) belongs to the macrolide antibiotic class. It treats ear infections, respiratory infections, sexually transmitted infections, and other bacterial conditions. While it may cause liver and heart rhythm effects, it is not associated with tendon problems.

Cephalexin (Keflex) is a cephalosporin-class antibiotic that treats respiratory infections, urinary tract infections, and bone infections—some of the same conditions as levofloxacin.

Your physician will recommend the most appropriate alternative based on the specific infection, your age, existing medical conditions, and other individual factors.