Disopyramide, Serum or Plasma

Test ID:

703672

CPT code:

80299

Clinical Use:

Evaluate toxicity; monitor therapeutic levels

Test Information:

Disopyramide shares electrophysiologic properties with quinidine and procainamide. Up to 80% of oral dose is absorbed. Half-life is 4 to 10 hours. Eighty percent of the drug is excreted in the urine. Dosage must be modified (dosage intervals prolonged) in patients with renal failure. Serious toxic effects are depression of myocardial contractility and disturbances in myocardial conduction. Other effects include dry mouth, constipation, urinary hesitancy, and blurred vision. Metabolite N-desisopropyl disopyramide is also pharmacologically active. Concomitant treatment with phenytoin may lead to decreased serum levels of disopyramide. There may be cumulative effect with other Class I antiarrhythmic drugs (lidocaine, procainamide).

Specimen Type:

Serum or plasma

Requested Volume:

1 ml

Minimum Volume:

.3 ml

Container Type:

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.