Flecainide, Serum
Use
Flecainide is a Class I cardiac antiarrhythmic agent indicated for treatment of paroxysmal supraventricular dysrhythmia, paroxysmal atrial fibrillation/flutter, and life-threatening ventricular dysrhythmias. Monitoring serum flecainide levels is useful for optimizing dosage, assessing toxicity, and evaluating patient compliance. Due to its narrow therapeutic window, precise monitoring is critical for minimizing adverse effects such as dizziness, visual disturbances, and other complications.
Special Instructions
Blood should be drawn immediately before the next scheduled dose to ensure accurate serum level measurement. The serum should be centrifuged and aliquoted into a plastic vial within 2 hours of collection. Special care must be taken to avoid the use of gel tubes, which can cause assay interference.
Limitations
Although serum flecainide levels between 0.2 and 1.0 mcg/mL are considered therapeutic, values above 1.0 mcg/mL are associated with potential toxicity, including severe cardiac adverse events. Specimens obtained from gel tubes or anticoagulated collections may interfere with assay results, leading to inaccurate measurements.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 3638-4
- 3638-4
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.5 mL
Minimum Volume
0.5 mL
Container
Red top (serum gel/SST are not acceptable)
Collection Instructions
Draw blood immediately before next scheduled dose. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Storage Instructions
Refrigerate the specimen if possible. It remains stable for up to 28 days under refrigerated, ambient, or frozen conditions.
Causes for Rejection
Gel tubes or anticoagulated specimens can cause assay interference.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 28 days |