AMITRIPTYLINE, serum (087-0460)

Synonyms: Elavil

CPT 4 Code: 80152

Test Order Mnemonic: AMITRIP

Test Includes: Nortriptyline

Lab: Clinical Chemistry

Request Form: Special Chemistry Form 2

Collection: Routine venipuncture. The optimum time for collection of blood specimen is between 10 and 14 hours after the last dose of medication for patients taking antidepressants once a day and just before the morning dose for patients who are on a divided dose schedule. Lab slip request must include date and time of specimen collection.

Storage Instructions: Process as soon as possible. Serum must be removed from the clot within 4 hours of draw and frozen.

Causes for Rejection: Serum not separated from the clot in 4 hours or less, blood collected with plasticizers or gel separators

Availability: Samples are received 24 hrs per day at Sample Management, Room 5.136 McCullough.

Turnaround Time: Routine: 3-5 days; test is performed on Tuesdays and Thursdays.

Special Instructions: Cyclobenzaprine (Flexeril) interferes with the quantitation of amitriptyline; therefore, amitriptyline cannot be quantitated if the patient is also on cyclobenzaprine. Some of the phenothiazines may also interfere.

Specimen: Blood

Volume: 7 mL blood

Minimum Volume: 1 mL serum

Container: Red-topped tube. Do not use SST/gel separator tube.

Reference Ranges: Therapeutic Range: 80-200 ng/mL (Total)

Critical Values: Potential Toxicity: > 500 ng/mL (Total)

Test Method: HPLC

Revised April 2007 by P. Harris