Test Code Billings Clinic: 8246 Mayo: GABA Gabapentin, Serum
Reporting Name
Gabapentin, SPerforming Laboratory
Mayo Clinic Laboratories in RochesterUseful For
Monitoring serum gabapentin concentrations
Assessing compliance
Adjusting dosage in patients
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST is not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Collect specimen immediately before next scheduled dose.
2. Within 2 hours of collection, centrifuge and aliquot serum into plastic vial.
Specimen Type
Serum RedSpecimen Minimum Volume
0.2 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Refrigerated (preferred) | 28 days | |
Ambient | 28 days | ||
Frozen | 28 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Reference Values
2.0-20.0 mcg/mL
Toxic Range: ≥25.0 mcg/mL
Interpretation
Therapeutic ranges are based on specimens collected immediately before the next dose (ie, trough).
Most epileptic patients show a response to the drug when the trough concentration is in the range of 2 to 20 mcg/mL. Therapeutic drug monitoring may be useful due to inter-individual variation in pharmacokinetics and dose-dependent bioavailability; specimens for measurements should be collected before the morning dose since the short half-life may affect the interpretation of the concentration.
Day(s) Performed
Monday through Saturday
Report Available
Same day/1 to 2 daysTest 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
80171
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
GABA | Gabapentin, S | 9738-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
80826 | Gabapentin, S | 9738-6 |
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Neurology Specialty Testing Client Test Request (T732)
-Therapeutics Test Request (T831)