Drug Interaction Report

Potassium and Losartan: Interaction Details

Name: Potassium and Losartan Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Potassium and Losartan 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

Potassium

Glu-K® K-Dur® 10 K-Dur® 20 K-Lor® K-Lyte® DS Effervescent Tablets K-Lyte® Effervescent Tablets K-Lyte/CL® 50 Effervescent Tablets K-Lyte/CL® Effervescent Tablets

Losartan

Arbli Cozaar Cozaar®

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Moderate

Can be significant — usually manageable with monitoring.

Minor

Moderate

Major

Contraindicated

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 11 documented Potassium interactions, 5 are rated moderate — including this one.

Onset

delayed

Evidence

theoretical

Severity

Moderate

What happens

Hyperkalemia

Interaction Deep Dive

Coadministration of angiotensin II receptor blockers and potassium may result in an increase in serum potassium. Patients on angiotensin II receptor blocking therapy should be alerted to the potential danger of excessive potassium in the diet, including potassium-containing salt substitutes or diet supplements.¹.

Why it happens (mechanism)

Additive potassium retention

Common questions

Can I take Potassium and Losartan together?

Hyperkalemia Always confirm with your pharmacist or prescriber before making any change.

How serious is the Potassium and Losartan 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 Potassium or Losartan 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 (1)

Product Information: DIOVAN(R) oral tablets, valsartan oral tablets. Novartis Pharmaceuticals Corp, East Hanover, NJ, 2007. DailyMed

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Potassium

Keep reading about Potassium

All Potassium interactions (11) Potassium drug information

Also serious with: Lisinopril Benazepril Captopril Fosinopril

Losartan

Keep reading about Losartan

All Losartan interactions (146) Losartan drug information

Also serious with: Aliskiren Sparsentan Lisinopril Voriconazole

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About our interaction database: depth, not breadth

HelloPharmacist doesn't license one of the big commercial interaction databases, so what you'll find here is not a complete list of every known drug interaction. Instead, each entry is researched, analyzed, and written up individually — documented from the published literature, reviewed by a pharmacist, and cited so you can check every source yourself.

If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

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.