CPT® Code 80336

A laboratory test identified by CPT® Code 80336 is utilized to measure the presence and levels of tricyclic and other cyclic antidepressants in biological samples such as urine, serum, or plasma. Tricyclic antidepressants (TCAs) and tetracyclic antidepressants (TeCAs) are classes of medications that primarily function by increasing the levels of certain neurotransmitters in the brain, specifically norepinephrine and serotonin, while simultaneously blocking the action of acetylcholine. These medications are commonly prescribed for a variety of conditions, including depression, anxiety disorders, fibromyalgia, chronic pain syndromes, and even for managing bedwetting in children. The tricyclic antidepressants include well-known drugs such as clomipramine (Anafranil), amitriptyline (Elavil), desipramine (Norpramin), nortriptyline (Pamelor), doxepin (Sinequan), and trimipramine (Surmontil). On the other hand, tetracyclic antidepressants encompass medications like amoxapine (Asendin), loxapine (Loxapac, Loxitan), mirtazapine (Remeron, Avinza), and maprotiline (Ludiomil). To perform this test, a blood sample is typically obtained through a procedure known as venipuncture, which is separately reportable. Alternatively, a urine sample can be collected either by random voiding or through catheterization. The testing process employs advanced techniques such as quantitative liquid chromatography-tandem mass spectrometry for analyzing all TCAs, while high-performance liquid chromatography is specifically used for testing the TeCA loxapine. Additionally, amoxapine is assessed using quantitative high-performance liquid chromatography, and maprotiline is evaluated through quantitative gas chromatography. For mirtazapine, both quantitative gas chromatography and gas chromatography-mass spectrometry methods are utilized. It is important to note that CPT® Code 80335 is designated for testing one or two cyclical antidepressants, while Code 80336 is specifically for the analysis of three to five compounds. For evaluations involving six or more antidepressants, Code 80337 is applicable.