Drug Interaction Report

Amiloride and Lithium Carbonate: Interaction Details

A pharmacist-reviewed analysis of the Amiloride and Lithium Carbonate interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Amiloride

No brand names on record
+

Lithium Carbonate

Lithobid
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
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.

Of 49 documented Amiloride interactions, 7 are rated moderate — including this one.
Onset
delayed
Evidence
theoretical
Severity
Moderate

What happens

Increased lithium concentrations and lithium toxicity (weakness, tremor, excessive thirst, confusion)

Interaction Deep Dive

Generally, caution should be used when lithium and diuretics are used concomitantly because sodium loss may reduce the renal clearance of lithium and increase serum lithium levels, which may lead to lithium toxicity23. There are no case reports or clinical studies that document an interaction between lithium and amiloride. A similar diuretic, triamterene, has been reported to increase lithium excretion resulting in decreased lithium effectiveness 1. Sodium loss may reduce the renal clearance of lithium and increase serum lithium levels with an increased risk of lithium toxicity (Prod Info Lithium carbonate, 2002).

Why it happens (mechanism)

Decreased lithium clearance

Common questions

Can I take Amiloride and Lithium Carbonate together?

Increased lithium concentrations and lithium toxicity (weakness, tremor, excessive thirst, confusion) Always confirm with your pharmacist or prescriber before making any change.

How serious is the Amiloride and Lithium Carbonate interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Amiloride or Lithium Carbonate 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 (3)

  1. Hardman JG, Gilman AG, Limbird LE, et alHardman JG, Gilman AG, Limbird LE, et al: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th. Pergamon Press, New York, NY, 1996.
  2. Product Information: Eskalith(R), lithium carbonate. GlaxoSmithKline, Research Triangle Park, NC, 2003. DailyMed
  3. Product Information: Midamor(R), amiloride. Merck & Co Inc, West Point, PA, 1997. DailyMed
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Amiloride

Keep reading about Amiloride

All Amiloride interactions (49)
Also serious with: Acetaminophen And Codeine Benazepril Naproxen Perindopril
Lithium Carbonate

Keep reading about Lithium Carbonate

All Lithium Carbonate interactions (317) Lithium Carbonate drug information
Also serious with: Phenelzine Tranylcypromine Zuclopenthixol Feprazone
Beyond drug–drug

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:

Amiloride + Activated Charcoal American Hellebore American Mistletoe Tyramine Adrafinil Agmatine Algal Oil Andrographis + 135 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.