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Spironolactone (Serum/Plasma Concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of spironolactone, a medication used to manage high blood pressure and fluid retention, in your blood.

Quick summary

["Spironolactone helps regulate electrolytes and blood pressure; this test checks if your dose is working properly."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
73145-5
Short code
Spironolactone ind plt IgM SerPl Ql FC
Synonyms
Spironolactone ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
60
Ref high
170
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
83540
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to monitor your response to spironolactone therapy, check for side effects, or adjust your medication. It’s often done if you have conditions like high blood pressure, heart failure, or kidney problems.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re on a low-sodium diet, check with your doctor first, as it may affect results.

How the Test Works

Blood is collected and tested using an immunoassay method to detect spironolactone levels. The test measures how much of the medication is present in your serum or plasma.

What the Results Mean

Results help your doctor determine if your medication is at the right level to control your condition without causing unwanted side effects. Low levels may mean your dose isn’t working, while high levels could signal toxicity or improper metabolism.

Reference range

NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A

Specimen: serum

Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Spironolactone Level

Frequently asked questions

Your doctor may recommend follow-up tests if your spironolactone levels are consistently too low or too high, or if you experience symptoms like dizziness, irregular heartbeat, or excessive thirst.
Spironolactone is a potassium-sparing diuretic, so low levels might indicate poor absorption or drug interactions. High levels could suggest overdose or kidney issues. Always discuss results with your provider.
What does a normal spironolactone level mean for my health?
A normal level doesn’t have a single range—it depends on your dose, health condition, and other medications. Your doctor will interpret results in the context of your treatment plan and symptoms. If your level is outside expected ranges, further evaluation may be needed.
Can diet or other medications affect my spironolactone test results?
Yes. Certain foods (like high-sodium or potassium-rich foods) and medications (such as potassium supplements or NSAIDs) can influence blood levels. Always inform your doctor about all medications, supplements, and dietary changes before testing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy