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HelpTest Code LACO Lacosamide, Serum
Useful For
Monitoring serum concentrations of lacosamide to ensure compliance and appropriate dosing in specific clinical conditions (ie, severe kidney impairment, mild-to-moderate hepatic impairment, and kidney failure)
Reporting Name
Lacosamide, SSpecimen Type
SerumSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Collect specimen immediately before next scheduled dose.
2. For sustained-release formulations ONLY, collect specimen a minimum of 12 hours after last dose.
3. Centrifuge and aliquot serum into plastic vial within 2 hours of collection.
Specimen Minimum Volume
0.2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Clinical Information
Lacosamide is approved for adjunctive therapy to treat partial-onset seizures in epileptic patients aged 17 years and older. In clinical trials, the most common side effects were dizziness, headache, nausea, and double vision. Lacosamide is completely absorbed after oral administration with negligible first-pass metabolism. Peak serum concentrations occur 1 to 4 hours after oral dosing, and the elimination half-life is approximately 13 hours. Steady-state serum concentrations are achieved after 3 days of twice daily repeated administration. About 40% of the administered dose is eliminated by the renal system unchanged, and 30% is metabolized by hepatic isoenzymes (CYP2C9, CYP2C19, and CYP3A4) to the O-desmethyl inactive metabolite. The relationship between lacosamide serum concentrations and its efficacy or adverse effects is not well established. However, central nervous system toxicity has been associated with higher drug concentrations in serum.
Reference Values
Patients receiving therapeutic doses usually have lacosamide concentrations of 1.0 to 10.0 mcg/mL.
Interpretation
The serum concentration should be interpreted in the context of the patient's clinical response and may provide useful information in patients showing poor response or adverse effects, particularly when lacosamide is co-administered with other anticonvulsant drugs.
Toxic ranges are not well established but occur more frequently when concentrations are greater or equal to 20 mcg/mL.
Cautions
Abnormalities in liver function tests (eg, alanine aminotransferase) have been observed in controlled trials in adult patients with partial-onset seizures who were taking 1 to 3 concomitant antiepileptic drugs.
Method Description
Lacosamide and the internal standard are separated from other serum constituents by high-performance liquid chromatography with analysis on a tandem mass spectrometer equipped with an electrospray ion source using multiple reaction monitoring.(Unpublished Mayo method)
Day(s) Performed
Monday through Saturday
Report Available
Same day/1 to 4 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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
80235
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LACO | Lacosamide, S | 59297-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 62772 | Lacosamide, S | 59297-2 |
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics