Spironolactone (Serum or Plasma Concentration)
This test measures the amount of spironolactone, a medication used to manage high blood pressure, fluid retention, and certain kidney conditions.
["Spironolactone helps balance electrolytes and blood pressure; abnormal levels may indicate side effects or effectiveness issues."]
Key facts at a glance
- LOINC
- 3428-0
- Short code
- CANR-U
- Synonyms
- Canrenone Ur Ql
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, preservative-free urine collection container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- High-Performance Liquid Chromatography (HPLC) with tandem mass spectrometry (LC-MS/MS) or immunoassay
- CPT
- 83789
- SNOMED
- 396892008
- Specimen volume
- 10-50 mL of random or 24-hour urine collection
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–96 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to check if spironolactone is working properly, monitor side effects like high potassium levels, or adjust your dose. It’s often done when you’re taking this medication for conditions like hypertension, heart failure, or kidney disease.
What Does the Test Involve?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure spironolactone levels. No special preparation is usually needed, but your doctor may advise fasting or avoiding certain medications before the test.
What Are Common Results?
Results are compared to a reference range provided by your lab. Low levels may suggest the medication isn’t working as intended, while high levels could indicate side effects like dizziness, irregular heartbeat, or excessive potassium.
What Does It Mean If Results Are Abnormal?
If your spironolactone levels are too low, your doctor might increase your dose or check for other medications interfering with it. High levels could mean you need to adjust your medication or avoid certain foods (like potassium-rich ones) to prevent complications.
Reference range
Reference values are qualitative (presence/absence). Canrenone is typically not detected in urine of individuals not receiving spironolactone therapy. Therapeutic monitoring ranges vary by clinical context and dosing.N/A
No special preparation required. Patient should be queried regarding spironolactone or potassium-sparing diuretic use, as canrenone is the active metabolite of spironolactone.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Spironolactone Level
Frequently asked questions
Why might my doctor want to check my spironolactone levels regularly?
Can I eat or drink anything before this test?
What should I do if I feel dizzy or have an irregular heartbeat after taking spironolactone?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 16, 2026. · Read our editorial policy