Sodium Bicarbonate and Chloroquine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sodium Bicarbonate
Chloroquine
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 efficacy of chloroquine
Interaction Deep Dive
Antacids and kaolin can reduce absorption of chloroquine; an interval of at least 4 hours between intake of these agents and chloroquine should be observed21. The peak plasma concentration and bioavailability of chloroquine was decreased by concomitant administration of magnesium trisilicate 3. Avoid use of magnesium trisilicate and other magnesium-containing antacids in patients taking chloroquine for the treatment or prophylaxis of malaria 4.
Why it happens (mechanism)
Reduced absorption of chloroquine
Literature reports
1 report — tap to read
a) Six healthy male volunteers ingested 1 gram of chloroquine diphosphate (600 mg of chloroquine base) to establish control parameters in a study to determine the effect of concomitant chloroquine with magnesium trisilicate and kaolin. During the test periods, the subjects were given magnesium trisilicate 1 gram or kaolin 1 gram every eight hours, beginning 24 hours prior to chloroquine administration. Maximum concentration (Cmax) of chloroquine during chloroquine monotherapy was 184.5 mcg/L and decreased to 142 mcg/L during coadministration with magnesium trisilicate. Other chloroquine parameters which decreased during combined therapy with chloroquine and magnesium trisilicate included Tmax (6.04 hours vs. 5.86 hours) and AUC from time zero to 144 hours after drug administration (9630 mcg/hr/L vs. 7878 mcg/hr/L). The decreased Cmax and AUC reflect the adsorption of chloroquine onto the magnesium trisilicate, resulting in a lesser amount of drug available for systemic absorption 3.
Common questions
Can I take Sodium Bicarbonate and Chloroquine together?
Decreased efficacy of chloroquine Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sodium Bicarbonate and Chloroquine interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Sodium Bicarbonate or Chloroquine 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 (4)
- Product Information: Chloroquine phosphate oral tablets, chloroquine phosphate oral tablets. Rising Pharmaceuticals Inc (per DailyMed), Saddle Brook, NJ, 2018. DailyMed
- US Food & Drug Administration (FDA): Fact sheet for health care providers emergency use authorization (EUA) of chloroquine phosphate supplied from the strategic national stockpile for treatment of COVID-19 in certain hospitalized patients. US Food & Drug Administration (FDA). Silver Spring, MD. 2020.
- McElnay JC, Mukhtar HA, D'Arcy PF, et al: The effect of magnesium trisilicate and kaolin on the in vivo absorption of chloroquine. J Trop Med Hygiene 1982; 85:159-163.
- Iwuagwu MA & Aloko KS: Adsorption of paracetamol and chloroquine phosphate by some antacids. J Pharm Pharmacol 1992; 44:655-658. PubMed
Keep reading about Sodium Bicarbonate
Keep reading about Chloroquine
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist