Calcium and Levofloxacin: what the published research says
PubMed indexes 8 records that name Calcium and Levofloxacin together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to Calcium and Levofloxacin. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.
The research
8 studies naming Calcium and Levofloxacin.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
“These results indicate that multivalent cations such as calcium should be maximally separated from oral levofloxacin administration in adult patients with cystic fibrosis to prevent this drug interaction, thereby better optimizing antibiotic efficacy and decreasing the potential for resistance development.”
Journal of clinical pharmacology · 2003 · PMID 12751275
Clinical TrialRandomized Controlled Trial
“Due to the lack of change in overall exposure, it is thought that rather than a chelation interaction, levofloxacin and components of the orange juices competed for intestinal transport mechanisms such as P-glycoprotein and organic anion-transporting polypeptides, which resulted in the discovered interaction.”
Australian endodontic journal : the journal of the Australian Society of Endodontology Inc · 2026 · PMID 41782171
“The calcium silicate-based group recorded the highest median (IQR) percentage of dead bacteria at 56.33 (10.03), followed by Simvastatin 44.88 (7.30), CH 41.70 (12.53), Levofloxacin 35.99 (3.78), and the positive control group 3.61 (1.01). These findings suggest that these intracanal medicaments demonstrate promising antibiofilm activity, with further investigations needed.”
The Journal of antimicrobial chemotherapy · 2020 · PMID 32428235
Human subjects
“The activity of omadacycline against UTI organisms was lower in urine relative to standard medium and was negatively impacted by magnesium. Omadacycline displayed slightly reduced activity when excess calcium was present, but, overall, the differences were ≤2-fold. These observations should be considered along with the pharmacokinetics of the agent for clinical context.”
International journal of pharmaceutics · 2015 · PMID 26002570
“Also, the lactose-modified BC matrix, with a more porous structure, has already proved to enhance antibiotic release from the BC inner matrix. This novel BC composite biomaterial has shown improved mechanical integrity, biocompatibility maintenance, and sustained release of levofloxacin, with concentrations over the minimum inhibitory concentration values after a 48h while maintaining antibacterial activity over an 8-week period against Staphyloccocus aureus and…”
Names Calcium and Levofloxacin together in an interaction, co-administration, or pharmacokinetic context.
Limitations
What this evidence cannot tell you.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.
Nearby evidence
Other pairs with published research.
Pages covering Calcium or Levofloxacin alongside a different substance.
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Calcium, Levofloxacin, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
