Skip to content

Metoprolol concentration in serum/plasma (quantitative drug level)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of metoprolol, a beta-blocker medication, in your blood to check if it’s working as intended and to ensure safe dosing.

Quick summary

["This test helps monitor your beta-blocker medication levels for proper treatment and safety."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73272-7
Short code
Metoprolol ind plt IgM SerPl Ql FC
Synonyms
Metoprolol ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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 This Test Is Done

Your healthcare provider may order this test if you’re taking metoprolol (a medication for high blood pressure, heart conditions, or angina) to verify your dose is appropriate. It helps ensure you’re neither too low (risking symptoms like dizziness or heart palpitations) nor too high (which could cause side effects like fatigue or breathing difficulties).

How the Test Works

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed using an immunoassay method to detect metoprolol levels. Results are reported in micrograms per milliliter (mcg/mL).

What to Expect Before the Test

No special preparation is needed, but inform your provider if you’re taking other medications, have allergies, or are pregnant. Avoid eating or drinking anything (except water) for 1 hour before the test if instructed.

What the Results Mean

Results help your doctor adjust your dose if needed. While reference ranges vary by lab, they’re used to guide safe dosing rather than diagnose conditions directly. Always discuss results with your provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Metoprolol Blood Level

Frequently asked questions

What could cause abnormal results?
Abnormal levels may indicate improper dosing, poor absorption, or drug interactions. High levels could suggest overmedication, while low levels may mean the medication isn’t working as expected. Always consult your provider for interpretation.
How often should this test be done?
Frequency depends on your condition and medication regimen. Your provider will determine if regular monitoring is needed, such as every few weeks for stable patients or more often if symptoms change.
Can I eat or drink before this test?
Check with your provider first—some tests require fasting, but metoprolol levels are typically checked without dietary restrictions unless specified otherwise.
  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 16, 2026. · Read our editorial policy