Test Code HYPOG Hypoglycemic Agent Screen, Serum
Reporting Name
Hypoglycemic Agent Screen, SUseful For
Evaluation of suspected insulinoma characterized by hypoglycemia and increased serum insulin concentration
Detecting drugs that stimulate insulin secretion
Drugs detected by this procedure are:
-The first-generation sulfonylureas: chlorpropamide (Diabinese), tolazamide, and tolbutamide (Orinase)
-The second-generation sulfonylureas: glimepiride (Amaryl), glipizide (Glucotrol), and glyburide (Glibenclamide)
-The meglitinides: repaglinide (Prandin) and nateglinide (Starlix)
-The thiazolidinediones: pioglitazone (Actos) and rosiglitazone (Avandia)
This test is not intended for therapeutic drug monitoring but could be used to monitor compliance.
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Serum RedSpecimen Required
Patient Preparation: Specimen must be collected during an episode of hypoglycemia.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume:1.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Frozen (preferred) | 28 days | |
Refrigerated | 28 days | ||
Ambient | 7 days |
Reference Values
Negative
Screening cutoff concentrations
Chlorpropamide: 100 ng/mL
Glimepiride: 20 ng/mL
Glipizide: 5 ng/mL
Glyburide: 5 ng/mL
Nateglinide: 5 ng/mL
Pioglitazone: 20 ng/mL
Repaglinide: 5 ng/mL
Rosiglitazone: 20 ng/mL
Tolazamide: 50 ng/mL
Tolbutamide: 20 ng/mL
Note: If a drug is detected at a concentration greater than the cutoff, the report will indicate that specific drug is positive. The test cutoff listed for each drug is lower than the concentration that will cause increased insulin and decreased glucose.
Day(s) Performed
Monday, Wednesday, Friday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80377
G0480-(if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
HYPOG | Hypoglycemic Agent Screen, S | 68318-5 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
21295 | Chlorpropamide | 48329-7 |
21298 | Glimepiride | 48325-5 |
21299 | Glipizide | 48326-3 |
21300 | Glyburide | 48327-1 |
609767 | Nateglinide | 49487-2 |
609768 | Pioglitazone | 100351-6 |
21301 | Repaglinide | 48328-9 |
609769 | Rosiglitazone | 100352-4 |
21296 | Tolazamide | 21566-5 |
21297 | Tolbutamide | 21567-3 |
Clinical Information
The metabolic and hormonal profiles of insulinoma and sulfonylurea-induced hypoglycemia are identical. Therefore, in the evaluation of the hypoglycemic patient, the possible use of oral hypoglycemic agents as the cause for low blood glucose and elevated serum insulin must be considered. Absence of hypoglycemic drugs in serum during an episode of low blood glucose should be demonstrated before considering pancreatic exploration for suspected insulinoma.
Interpretation
Use of hypoglycemic agents outside of the context of treatment of type 2 diabetes is likely to cause hypoglycemia associated with elevated serum insulin. Patients presenting with hypoglycemia due to ingestion of a first-, second-, or third-generation hypoglycemic agents will have drug present in serum greater than the minimum effective concentration (see Reference Values). Presence of drug indicates that the patient has recently ingested a hypoglycemic agent.
Method Description
Serum specimens are subjected to organic extraction. The extract is analyzed by liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.
Highlights
If hypoglycemia is the result of an insulin-stimulating drug, this test will detect the drug at physiologically significant concentrations during an episode of hypoglycemia.