Amantadine (Symmetrel)
Use
This test measures the concentration of amantadine in plasma or serum to monitor therapeutic levels and assess toxicity. Amantadine is an antiviral and antiparkinsonian agent. Monitoring is crucial because therapeutic levels vary and toxicity is reported at concentrations greater than 2000 ng/mL. Monitoring can help ensure adequate dosage and avoid adverse effects, particularly in patients with renal impairment or those taking other medications that may interact with amantadine.
Special Instructions
Specimen collection requires either plasma or serum. For plasma, collect blood in a sodium heparin green-top tube, avoiding plasma gel tubes. For serum, use a red-top tube and avoid serum gel tubes. Both specimens require 3 mL of plasma or serum and must be refrigerated. Minimum specimen volume is 0.6 mL, which is sufficient for a single test attempt. Specimens should be transported refrigerated, ambient for up to 72 hours, and frozen for long-term storage for up to 180 days.
Limitations
Interpretation of results is limited by the lack of established therapeutic range for amantadine; therefore, clinicians should consider individual patient factors when interpreting results. Hemolysis, lipemia, icterus, and other conditions do not automatically invalidate the sample, but care should be taken in handling and processing specimens. External factors such as other medications may affect amantadine levels, requiring clinical correlation.
New York Approved
Methodology
Mass Spectrometry (GC-NPD)
Biomarkers
LOINC Codes
- 3317-5
- 3317-5
Result Turnaround Time
5-9 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
3 mL
Minimum Volume
0.6 mL
Container
Plastic vial
Collection Instructions
Draw blood in a green-top (sodium heparin) tube, avoid plasma gel tube. Spin down and send plasma refrigerated.
Storage Instructions
Refrigerated preferred up to 14 days, ambient up to 72 hours, frozen up to 180 days.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 14 days |
| Frozen | 180 days |