Gabapentin

Pathology category

Biochemistry - referred tests

Code

GABA

Referral code

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Test information

Anticonvulsant drug. TDM is useful when non-compliance or toxicity is suspected Approx time to steady state 1-2 days. Target 2-20mg/L. Absorption of gabapentin is very rapid with peak conc at 2-3h. Elimination half life 5-7h, necessitates dosing 3 times daily. Drug is eliminated entirely via kidneys as unchanged compound. CNS adverse effects are similar to other anticonvulsant drugs

Guidelines

Pre-analytical

Samples should be taken pre-dose (trough)

Reference range

2-20 mg/L

Tube type

Tube type info

Li Hep/ EDTA/ SST

Special requirements

Plasma or serum

Minimum volume

200 uL

Assay frequency

TAT Inpatient (urgent)

TAT Inpatient

4 weeks

TAT GP/Outpatient

4 weeks

Referral lab

Regional Toxicology Laboratory, City Hospital