Flecainide (Tambocor®), Serum
| Flecainide (Tambocor®), Serum | | | |
| Number | | 085662 |
| CPT | | 82491 |
| Synonyms | | Tambocor® |
| Specimen | | Serum or plasma |
| Volume | | 3 mL |
| Minimum Volume | | 1.1 mL |
| Container | | Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube |
| Collection | | Draw immediately prior to next dose unless otherwise instructed. Transfer separated serum or plasma to a plastic transport 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. |
| Storage Instructions | | Refrigerate |
| Causes for Rejection | | Gel-barrier tube |
| Reference Interval | | Therapeutic: 0.2-1.0 μg/mL |
| Use | | 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. |
| Methodology | | High-pressure liquid chromatography (HPLC) |
| 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 12-27 hours) in adults, although in children it has been reported to be 8 hours. Steady-state levels are achieved in 3-5 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. |
| References | | AMA, Division of Drugs and Toxicology, Drug Evaluations Subscription, Chicago, IL: American Medical Association, Winter 1993. Jurgens G, Graudal NA, and Kampmann JP, “Therapeutic Monitoring of Antiarrhythmic Drugs,” Clin Pharmacokinet, 2003, 42(7):647-63. Mosby's Drug Consult, St Louis, MO: Elsevier Mosby, 2006. |
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