Serum or Plasma Loperamide Concentration (Quantitative)
This test measures the amount of the opioid loperamide in your blood or plasma/serum. Loperamide is used to treat diarrhea and may be present in your system after taking this medication.
["Knowing your loperamide level helps doctors monitor how your body is processing the drug."]
Key facts at a glance
- LOINC
- 73298-2
- Short code
- Loperamide ind plt IgM SerPl Ql FC
- Synonyms
- Loperamide 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 loperamide and experiencing unusual side effects, such as excessive drowsiness, confusion, or slow heart rate. It may also be used to assess drug levels in specific cases, like overdose evaluation or therapeutic drug monitoring.
What to Expect Before the Test
No special preparation is needed. You may have blood drawn from a vein in your arm, typically in a lab setting. If you’re taking loperamide, it’s important to inform your doctor or technician beforehand.
What the Test Results Mean
Results are interpreted by your healthcare provider based on your medical history, symptoms, and other factors. High levels may indicate overdose or improper metabolism, while low levels might suggest insufficient medication absorption.
Common Uses and Considerations
This test is primarily used in clinical settings where precise drug monitoring is critical, such as in cases of suspected overdose, drug interactions, or unusual reactions to loperamide.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Loperamide is an opioid used to slow bowel movements in diarrhea. Abnormal levels can affect its effectiveness or pose risks like respiratory depression. Your doctor will assess results in the context of your symptoms and medical history.
Short name
Loperamide Level
Frequently asked questions
Why might my doctor request this test?
What are typical reference ranges?
How long does it take to get results?
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