Test Code FLEC Flecainide, Serum
Reporting Name
Flecainide, SUseful For
Optimizing flecainide dosage
Assessing flecainide toxicity
Monitoring compliance
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Serum RedSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Refrigerated (preferred) | 28 days | |
Ambient | 28 days | ||
Frozen | 28 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Reference Values
Trough Value
0.2-1.0 mcg/mL: Therapeutic concentration
>1.0 mcg/mL: Toxic concentration
Day(s) Performed
Monday through Friday
CPT Code Information
80181
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
FLEC | Flecainide, S | 3638-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
9243 | Flecainide, S | 3638-4 |
Clinical Information
Flecainide (Tambocor) is a Class I cardiac antiarrhythmic agent indicated for treatment of paroxysmal supraventricular dysrhythmia, paroxysmal atrial fibrillation/flutter, and life-threatening ventricular dysrhythmias. After oral administration, flecainide is almost completely absorbed and peak concentrations are attained in approximately 3 hours. The half-life averages approximately 20 hours but is widely variable (12 to 27 hours), and steady-state concentrations are typically achieved in approximately 5 days. Flecainide is eliminated from blood by hepatic metabolism, as well as renal clearance; significant changes in either organ system will cause impaired clearance. Common adverse effects include dizziness, visual disturbances, and dyspnea. Mild-to-moderate toxicity is associated with dizziness, visual disturbances, headache, nausea, fatigue, palpitations, and chest pain. Visual hallucinations and dysarthria may occur at toxic serum concentrations. Death can occur from hypotension, respiratory failure, and asystole.
Interpretation
Flecainide is most effective in premature ventricular contractions suppression at serum concentrations in the range of 0.2 to 1.0 mcg/mL.
Serum concentrations above 1.0 mcg/mL are associated with a high rate of cardiac adverse experiences such as conduction defects or bradycardia.
Cautions
Specimens that are obtained from gel tubes or anticoagulate collections can cause assay interference.
Method Description
Protein is precipitated from serum and following centrifugation the supernatant is diluted and analyzed by liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)