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Thiopental concentration (serum/plasma)

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

This test measures the amount of thiopental, a short-acting anesthetic drug, in your blood. It is often used to monitor levels during anesthesia or sedation.

Quick summary

["This test helps ensure your safe and controlled administration of anesthesia."]

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

Key facts at a glance

LOINC
4441-2
Short code
Thiopental Dose
Synonyms
Thiopental Dose
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 receiving thiopental as part of anesthesia or sedation. It helps track how your body is responding to the medication to prevent overdose or underdose.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein for blood collection, which is usually quick and painless.

How the Test Works

Blood is drawn and sent to a lab, where it is analyzed to measure thiopental levels. The test detects the drug’s presence and concentration in your bloodstream.

Possible Results and Interpretation

Results are used to guide dosing adjustments during anesthesia. Your provider will interpret the results in the context of your medical condition and treatment plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Thiopental Level

Frequently asked questions

What does a low or high thiopental level mean?
Low levels may indicate insufficient anesthesia effect, while high levels could pose risks like respiratory depression or overdose. Your provider will monitor closely and adjust medication as needed.
Can thiopental affect other medications?
Yes, thiopental interacts with other sedatives, pain medications, or anesthesia drugs. Always inform your healthcare team about all medications you’re taking to avoid dangerous effects.
How long does it take to get results?
Results are typically available within a few hours to a couple of days, depending on lab processing times. Your provider will discuss them with you during follow-up.
  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