| Laboratory: | Clinical Biochemistry |
| Test Name: |
GABAPENTIN - (P)
Test Code:
GABA
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| Clinical Information: |
Gabapentin is an antiepileptic drug (AED) widely used for the treatment of focal seizures, neuropathic pain syndromes, and other neurologic disorders. Gabapentin exhibits linear elimination kinetics within the therapeutic dosage range, negligible protein binding (<3%), and is not significantly metabolized. The drug is eliminated almost exclusively by renal excretion as unchanged parent compound, making renal function the primary determinant of systemic exposure. Consequently, substantial variability in serum concentrations may occur among patients with differing degrees of renal impairment, advanced age, or altered renal clearance.
Test Indications: Routine TDM of gabapentin is not generally required because a clear concentration-response relationship has not been firmly established. However, TDM can be valuable in specific clinical situations, including assessment of medication adherence, investigation of therapeutic failure, evaluation of suspected toxicity, dose optimization in patients with renal dysfunction, and management of special populations such as children, older adults, and critically ill patients. Measurement of serum gabapentin concentrations may also assist in establishing an individual's therapeutic baseline concentration during periods of optimal clinical response. Reference values pertain to trough blood collection time. |
| Collection Devices: |
Do not use separator gel.
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| Specimen Required: |
Plasma: 2.0 mL
Serum collected without gel is also acceptable. |
| Referral: |
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| Requisition: | |
| Reference Values: | |
| Availability: |
Within 2 Weeks
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| See Also: | |
| More Information: |
Store and send plasma frozen to In-Common Laboratories.
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