NutriStack
Aluminum/Magnesium Hydroxide and Ciprofloxacin, timing-sensitive.
Aluminum and magnesium in antacids form insoluble chelate complexes with ciprofloxacin in the gut, dramatically reducing antibiotic absorption. Studies have shown bioavailability reductions of 50 to 90 percent when taken together, which can drop ciprofloxacin levels below the threshold needed to clear infection. This is one of the most clinically significant absorption interactions for fluoroquinolones.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Aluminum/Magnesium Hydroxide and Ciprofloxacin
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Strong
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored timing-sensitive row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Timing Sensitive · Strong evidence
Timing Sensitive
What is happening. Aluminum and magnesium in antacids form insoluble chelate complexes with ciprofloxacin in the gut, dramatically reducing antibiotic absorption. Studies have shown bioavailability reductions of 50 to 90 percent when taken together, which can drop ciprofloxacin levels below the threshold needed to clear infection. This is one of the most clinically significant absorption interactions for fluoroquinolones.
Mechanism. Polyvalent cations (Al3+, Mg2+) bind to the 4-oxo and 3-carboxyl groups on the fluoroquinolone ring, forming nonabsorbable chelate complexes in the small intestine and blocking enterocyte uptake.
Recommendation. Take ciprofloxacin at least 2 hours before or 6 hours after any aluminum or magnesium hydroxide antacid. Do not co-administer in the same dose.
Minimum separation. 360
Sources (3)
- Eljaaly K, Helal A, Almandeel T, Algarni R, Alshehri S. Multivalent cations interactions with fluoroquinolones or tetracyclines: A cross-sectional study. Saudi J Biol Sci. 2021;28(12):6929-6932. PMID 34866992
- Sultana N, Arayne MS, Hussain F. In vitro monitoring of ciprofloxacin antacids interactions by UV & HPLC. Pak J Pharm Sci. 2005;18(4):23-31. PMID 16380354
- Wiesner A, Zagrodzki P, Gawalska A, Paśko P. Together or Apart? Revealing the Impact of Dietary Interventions on Bioavailability of Quinolones: A Systematic Review with Meta-analyses. Clin Pharmacokinet. 2024;63(6):773-818. PMID 38807006
Stack Score
How this pair moves the number.
Effect on the composite score
If both Aluminum/Magnesium Hydroxide and Ciprofloxacin are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.