Prescription ·Strong evidence ·Reviewed May 2026
A third-generation (respiratory) fluoroquinolone with broad-spectrum activity against gram-positive (including S. pneumoniae), gram-negative, and atypical organisms. Often called a 'respiratory fluoroquinolone' due to reliable pneumococcal activity. Used for community-acquired pneumonia, hospital-acquired pneumonia, acute bacterial sinusitis, chronic bacterial prostatitis, complicated UTI, and skin infections. Reserved for conditions without safer alternatives due to FDA black box warnings.
The bottom line
Evidence rating strong. Most-documented uses: treats community-acquired pneumonia (including drug-resistant s. pneumoniae), treats acute bacterial sinusitis, treats complicated urinary tract infections. 10 sources indexed (2006–2026), with 10 interaction records on file.
Core mechanism
The L-isomer of ofloxacin, approximately twice as potent. Inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, trapping the enzyme-DNA complex and causing lethal double-stranded DNA breaks. Has enhanced activity against gram-positive organisms (particularly S. pneumoniae) compared to ciprofloxacin, making it effective for respiratory infections. Exhibits concentration-dependent bactericidal activity.
Oral bioavailability approximately 99%. Do NOT take with calcium, iron, magnesium, zinc, or aluminum-containing antacids, chelation reduces absorption by up to 90%. Separate from antacids, sucralfate, and mineral supplements by at least 2 hours before or 2 hours after dosing.5
Nutrients this medication can lower over time, and what to replace.
Fluoroquinolones can increase renal magnesium wasting and can also bind supplemental magnesium in the gut during active treatment.
Calcium binds levofloxacin in the gut and reduces its absorption by 30 to 50 percent. This applies to calcium supplements, calcium-fortified foods, and dairy. Lower antibiotic exposure can cause treatment failure for serious infections.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after calcium supplements, dairy, or calcium-fortified products.
Iron supplements bind levofloxacin in the gut, forming insoluble chelate complexes that dramatically reduce antibiotic absorption. Bioavailability reductions of 30 to 60 percent are typical with concurrent dosing. Subtherapeutic levofloxacin levels can cause treatment failure.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after any iron supplement. Do not co-administer.
Iron bisglycinate, despite being a chelated and gentler form, still releases iron available for fluoroquinolone chelation in the gut. Co-administration with levofloxacin reduces antibiotic absorption and can cause treatment failure.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after iron bisglycinate. Do not take in the same dose.
Magnesium glycinate chelates levofloxacin in the gut, dramatically reducing antibiotic absorption. The bioavailability decrease can exceed 40 percent, which may cause treatment failure for serious infections.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after magnesium glycinate. Do not co-administer.
Zinc supplements bind levofloxacin in the gut and reduce its absorption by approximately 20 to 50 percent. Reduced antibiotic exposure can cause treatment failure, particularly in serious infections such as pneumonia or pyelonephritis.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after zinc supplements. Do not take in the same dose.
Aluminum and magnesium in antacids form insoluble chelate complexes with levofloxacin in the gut, reducing antibiotic absorption by 50 percent or more. This is one of the most clinically significant absorption interactions for levofloxacin.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after any aluminum or magnesium hydroxide antacid. Do not co-administer in the same dose.
Calcium carbonate binds levofloxacin in the gut and reduces its absorption substantially. This applies whether calcium carbonate is taken as an antacid or as a calcium supplement.
Recommendation: Take levofloxacin at least 2 hours before or 2 hours after calcium carbonate. Do not co-administer.
Probiotic supplementation during levofloxacin therapy reduces the incidence of antibiotic-associated diarrhea and helps preserve gut microbiome diversity. The benefit is greatest when probiotics are started early in the course and continued briefly after antibiotic completion.
Recommendation: Take probiotics throughout your levofloxacin course, separated by at least 2 hours from each antibiotic dose. Continue for at least 1 week after the antibiotic ends.
Zinc picolinate can bind fluoroquinolone antibiotics in the gut and reduce absorption. Levofloxacin exposure can fall when taken with multivalent cations, which may lead to antibiotic failure or resistance, especially for serious infections. This is preventable by separating doses.
Recommendation: Take levofloxacin at least 2 hours before or 6 hours after zinc picolinate. Do not take zinc at the same time as the antibiotic, even in a multivitamin. If you accidentally took them together, ask your prescriber or pharmacist whether the levofloxacin dose needs to be retimed.
Levofloxacin can chelate with multivalent cations. PubMed-indexed in vitro work found complex formation between levofloxacin and a manganese-containing gastrointestinal diagnostic drug, while fluoroquinolone reviews and human cation studies support reduced absorption as the clinically important concern. Taking manganese at the same time may reduce levofloxacin exposure.
Recommendation: Separate manganese supplements from levofloxacin by at least 2 hours, and follow any stricter directions on your prescription label. Do not take levofloxacin with mineral blends, multivitamins, or antacids unless your pharmacist confirms the timing. Seek care if infection symptoms persist or worsen.
Numbered references. Citations throughout the page link here.
Ding Y, Zeng X, Zou J et al.. Population pharmacokinetics of levofloxacin: a systematic review. Drug metabolism reviews. 2026
Duong T, Brigden J, Simon Schaaf H et al.. A Meta-Analysis of Levofloxacin for Contacts of Multidrug-Resistant Tuberculosis. NEJM evidence. 2025
Xue Z, Xiang Y, Li Y et al.. A systematic review and meta-analysis of levofloxacin and ciprofloxacin in the treatment of urinary tract infection. Annals of palliative medicine. 2021
Gisbert JP, Morena F. Systematic review and meta-analysis: levofloxacin-based rescue regimens after Helicobacter pylori treatment failure. Alimentary pharmacology & therapeutics. 2006
Phillips PPJ, Peloquin CA, Sterling TR et al.. Efficacy and Safety of Higher Doses of Levofloxacin for Multidrug-resistant Tuberculosis: A Randomized, Placebo-controlled Phase II Clinical Trial. American journal of respiratory and critical care medicine. 2025
Junqi Z, Jie C, Jinglin W et al.. A retrospective study of the efficacy and safety of levofloxacin in children with severe infection. Frontiers in pediatrics. 2024
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