Moxifloxacin and Aluminum Carbonate, Basic: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Moxifloxacin
Aluminum Carbonate, Basic
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased oral moxifloxacin effectiveness
Interaction Deep Dive
A significant decrease in the oral bioavailability of moxifloxacin (approximately 40%) was observed when coadministered with Maalox(R)12. When a single dose of moxifloxacin 400 mg was administered two hours before, concurrently, or four hours after a single dose of an antacid preparation containing aluminum hydroxide and magnesium hydroxide to 12 healthy volunteers, there was a 26%, 60%, and 23% decrease in the moxifloxacin area under the concentration-time curve (AUC), respectively. Oral moxifloxacin should be administered at least four hours before or eight hours after an aluminum or magnesium containing product 3. Concomitant administration of calcium has been shown not to significantly affect bioavailability of moxifloxacin 5.
Why it happens (mechanism)
Decreased moxifloxacin absorption due to chelation
Literature reports
1 report — tap to read
a) Coadministration of aluminum- and magnesium-containing antacids with moxifloxacin impairs the absorption of moxifloxacin. Twelve healthy male subjects were enrolled in a randomized, nonblinded, 4-way crossover study. The four treatments consisted of a single dose of moxifloxacin 400 mg given alone, or with Maalox 70(R) suspension (aluminum hydroxide 900 mg and magnesium hydroxide 600 mg) administered simultaneous with, 4 hours before, or 2 hours after moxifloxacin. Administration of the antacid in the treatments including antacid was continued for 2 days. The rate and extent of moxifloxacin absorption are reduced when coadministered with Maalox70(R). The AUC of moxifloxacin is reduced by less than 27% when moxifloxacin is administered two hours before or 4 hours after ingestion of Maalox(R). The half-life was decreased by three hours. When moxifloxacin is administered two hours before or four hours after the antacid, the subjects had antibacterial exposure below the cut-off points (minimum values of AUC/MIC were 57 and those of Cmax/MIC were 3.8) suggesting that these drugs should not be administered simultaneously. Absorption of moxifloxacin is impaired by concurrent administration of Maalox70(R), an aluminum and magnesium-containing antacid. For maximal bactericidal effect it is recommended to stagger the administration of antacids and moxifloxacin either two hours before or four hours after the antacid 4.
Common questions
Can I take Moxifloxacin and Aluminum Carbonate, Basic together?
Decreased oral moxifloxacin effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Moxifloxacin and Aluminum Carbonate, Basic interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Moxifloxacin or Aluminum Carbonate, Basic need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (5)
- Anon: Moxifloxacin - close to ideal for respiratory infections. Scrip 1999; No. 2415:25.
- Barman-Balfour JA & Wiseman LR: Moxifloxacin (review). Drugs 1999; 57:363-373.
- Product Information: Avelox(TM), moxifloxacin hydrochloride. Bayer Corporation, West Haven, CT, 2003. DailyMed
- Stass H, Bottcher M, & Ochmann K: Evaluation of the influence of antacids and h2 antagonists on the abosrption of moxifloxacin after oral administration of a 400 mg dose to healthy volunteers. Clin Pharmacokinetic 2001; 40(1):39-48.
- Stass H, Wandel C, Delesen H, et al: Effect of calcium supplements on the oral bioavailability of moxifloxacin in healthy male subjects. Clin Pharmacokinet 2001; 40(Suppl 1):27-32.
Keep reading about Moxifloxacin
Keep reading about Aluminum Carbonate, Basic
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