Flecainide, Serum or Plasma

CPT: 80299
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Test Details


  • Tambocor™


Flecainide is used for the treatment and prophylaxis of supraventricular tachycardia, including AV nodal and AV reentrant tachycardia and atrial fibrillation in patients with normal or near-normal left ventricular function.


Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reference Interval

Therapeutic: 0.2−1.0 μg/mL

Additional Information

Flecainide is a Class 1C antiarrhythmic drug approved for the suppression of ventricular arrhythmias. The drug is well absorbed orally. Plasma half-life averages 20 hours (range 12 to 27 hours) in adults, although in children it has been reported to be eight hours. Steady-state levels are achieved in three to five days. Since 10% to 50% of the drug is eliminated in the urine as unchanged drug, impaired renal function will significantly prolong the plasma half-life. Clearance of flecainide can be accelerated by phenobarbital and rifampin. There are no significant metabolites of flecainide. Co-administration with digoxin increases serum digoxin by 20%; co-administration with propranolol increases both by 20% in serum and creates an additive pharmacological effect.

Specimen Requirements


Serum or plasma


3 mL

Minimum Volume

1.1 mL


Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube. Do not use a gel-barrier tube. The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel. Depending on the specimen volume and storage time, the decrease in drug level due to absorption may be clinically significant.


Transfer separated serum or plasma to a plastic transport tube. Draw immediately prior to next dose unless otherwise instructed.

Storage Instructions

Room temperature

Stability Requirements



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Gel-barrier tube

Clinical Information


American Medical Association, Division of Drugs and Toxicology. Drug Evaluations Subscription. Chicago, Ill: AMA, Winter 1993.
Jurgens G, Graudal NA, Kampmann JP. Therapeutic monitoring of antiarrhythmic drugs. Clin Pharmacokinet. 2003; 42(7):647-663. 12844326
Mosby's Drug Consult. St Louis, Mo: Elsevier Mosby; 2006.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
085662 Flecainide (Tambocor(TM)), S 3638-4 085662 Flecainide (Tambocor(TM)), S ug/mL 3638-4

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