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Drug Monitoring, Antidepressants, With Confirmation, Urine and Serum

Test code(s): 94031, 94032

Antidepressants are medications that can be used to treat mild, moderate, and severe major depression. These medications may also be used to treat anxiety and eating disorders as well as pain (fibromyalgia and neuropathic).

The pharmacologic actions of antidepressants are based upon the monoamine hypothesis: antidepressant effects result from inhibition of monoamine oxidase breakdown of monoamine neurotransmitters.

Examples of antidepressant drug classes include the following:

  • Selective serotonin reuptake inhibitors (SSRIs) Serotonin-norepinephrine reuptake inhibitors (SNRIs)
  • Serotonin modulators and stimulators (SMSs)
  • Serotonin antagonists and reuptake inhibitors (SARIs)
  • Norepinephrine reuptake inhibitors (NRIs)
  • Norepinephrine-dopamine reuptake inhibitors (NDRIs)
  • Tricyclic antidepressants (TCAs)
  • Tetracyclic antidepressants (TeCAs)
  • Monoamine oxidase inhibitors (MAOIs) 

Drug testing in the clinical setting can provide information that can improve patient care. The results of drug testing can often prompt important clinical discussions with patients. For example, absence of an expected drug could suggest poor adherence or diversion, whereas detection of a nonprescribed or illicit drug could raise concerns regarding substance misuse and potential drug interactions. Discrepancies between expected and actual results could also call attention to patient intolerance to adverse effects of medications or to potential medical factors affecting drug disposition.

The test codes are:

Test code 94032 is currently being performed at the Quest Diagnostics Nichols Institute, Chantilly and Valencia laboratories. Additional labs may be added at a later date.

Test code 94031 is currently being performed at the Quest Diagnostics Nichols Institute, Chantilly laboratory.

Test codes 70204 and 16903 are performed at multiple Quest laboratories.

Test Code 94032 and 94031

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is used for both the presumptive analysis and the definitive quantitative confirmation.

Multiple antidepressant drugs from various classes are included in the tests. A list of them and the associated cutoffs can be found on page 3.

Test codes 70204 and 16903

Mass spectrometry is used for definitive quantitation of amitriptyline and nortriptyline.

Negative results indicate absence of drug and/or metabolite or concentrations below the assay cutoff. Positive results indicate the presence of the respective drug and/or metabolite.

Yes. Antidepressant testing is considered a clinical test; therefore, the specimens may be placed in the same specimen bag (one patient per bag) with other clinical specimens.

If you have any questions regarding this information or require assistance with interpreting these drug test results, please contact a Quest Diagnostics toxicology specialist at 1.877.40.RXTOX (1.877.407.9869). Specialists are available to assist you Monday through Friday from 8 AM to 10 PM EST.

This FAQ is provided for informational purposes only and is not intended as medical advice. A clinician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

Document FAQS.188 Version: 1
Version 1: Effective 12/18/2019 to present
Version 0: Effective 03/26/2018 to 12/18/2019