CPT® Code 80335

A laboratory test identified by CPT® Code 80335 is utilized to measure the 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 the 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 involves sophisticated techniques such as quantitative liquid chromatography-tandem mass spectrometry for all TCAs, high-performance liquid chromatography specifically for the TeCA loxapine, and quantitative gas chromatography for both maprotiline and mirtazapine. This code, 80335, is specifically designated for testing one or two cyclical antidepressants, while codes 80336 and 80337 are reserved for testing three to five and six or more compounds, respectively.