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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Gabapentin

Test Code(s): GABA / HCGABA

CPT Code(s): 80171

Methodology: Liquid Chromatography

Clinical Significance: Anticonvulsant

Days Performed: Mon-Fri, dayshift.

Turnaround Time: Routine: 48 hours.

Specimen Requirements

Specimen: Blood

Collection Instructions: Collect specimen for trough level prior to next dose.

Collection Container: Preferred: Red top

Collection Volume: Preferred: 2 mL
Pediatrics: 1.5 mL

Sample Analyzed: Serum

Volume Required: Preferred: 1 mL
Pediatrics: 0.5 mL

Specimen Processing: Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.  

Unacceptable Criteria: Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.

Stability: Ambient: 14 days
Refrigerated: 14 days
Frozen: 14 days


Interpretive Guidelines:

Definitive therapeutic concentration for gabapentin has not been established. A serum concentration of 5.0-15.0 mcg/mL is generally considered to be therapeutic for individuals 18 years old and up. Steady-state concentrations are nearly proportional to dose with maximum levels in the ranges of 3.0-5.0 mcg/mL, 4.4- 6.6 mcg/mL, and 6.0-11.0 mcg/mL, respectively, for doses of 300, 400 and 600 mg three times daily. Trough levels range from 1-10 mcg/mL at doses of 300, 400 and 600 mg three times daily.

Critical Calls: View

Additional Information:

Result of "BELOW" indicates that the result is below the method detection limit of 0.1 mcg/mL. 


This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories.  This test meets the standards for clinical testing.  This test should not be regarded as investigational or for research use.  The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.


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