Triamterene and Lithium Carbonate: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Triamterene
Lithium Carbonate
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
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 toxicity (Prod Info Lithium carbonate, 2002). While triamterene is a diuretic, it acts distally in the nephron. The administration of triamterene has been reported to increase lithium excretion, resulting in decreased lithium effectiveness1. However, the manufacturer of triamterene cautions against the use of lithium and diuretics because of the increased potential for lithium toxicity 2.
Why it happens (mechanism)
Decreased lithium clearance
Common questions
Can I take Triamterene 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 Triamterene 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 Triamterene 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 (2)
- 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.
- Product Information: Dyrenium(R), triamterene. SmithKline Beecham Pharmaceuticals, Pittsburgh, PA, 1998. DailyMed
Keep reading about Triamterene
Keep reading about Lithium Carbonate
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.
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