Hydroxyzine is a prescription medication often used to manage anxiety, alleviate allergic reactions like hives and itching, and sometimes assist with sleep due to its mild sedative properties. This medication is an antihistamine that works by blocking histamine in the body and can also reduce activity in the central nervous system. Because hydroxyzine is a legally prescribed substance, individuals often wonder whether its presence might affect the results of a drug test.
How Drug Tests Work
Drug tests identify specific substances or their metabolic byproducts within a biological sample, typically targeting commonly abused drugs rather than a broad spectrum of prescription medications. Common matrices for drug testing include urine, blood, and hair, each offering different detection windows. Urine tests are frequently used for routine screenings, while blood tests may be employed for more precise detection of active drug presence. Hair tests provide an extended detection period, potentially identifying drug use over several months. Initial screening often uses immunoassay technology, which detects drug classes based on their chemical structure, while confirmatory tests use more precise methods to identify specific compounds.
Hydroxyzine and Standard Drug Panels
Hydroxyzine is generally not included in standard drug test panels, such as 5-panel or 10-panel screens. These panels are designed to detect illicit substances and commonly abused prescription drugs, including opioids, amphetamines, cocaine, cannabis, and benzodiazepines. Hydroxyzine is an antihistamine and is not classified as a controlled substance by agencies like the Drug Enforcement Administration. Its chemical structure and therapeutic uses differ significantly from the substances typically screened for.
Potential for Misidentification or False Positives
While hydroxyzine is not directly tested for, there is a rare possibility it could lead to a false positive result for other substances on an initial immunoassay drug screen. This can occur due to structural similarities between hydroxyzine and certain other compounds, such as tricyclic antidepressants (TCAs). Immunoassay tests are less specific and may mistakenly identify hydroxyzine’s chemical structure as that of a TCA, leading to a cross-reaction.
If an initial screening test yields an unexpected positive result, a more specific confirmatory test, such as Gas Chromatography-Mass Spectrometry (GC-MS) or Liquid Chromatography-Mass Spectrometry (LC-MS), is typically performed. These advanced methods can accurately differentiate hydroxyzine from other substances, thereby ruling out a false positive. The false positive rate for these confirmatory tests is very low, often less than 0.01 percent.
Addressing a Positive Result
If a drug test yields a positive result, especially one that might be attributed to hydroxyzine, it is important to communicate openly with the testing facility or employer. Providing documentation of a valid prescription for hydroxyzine is a crucial step. Medical Review Officers (MROs) are licensed physicians trained to review and interpret drug test results, including those involving prescription medications.
When a non-negative result occurs, the MRO will typically contact the individual to discuss any legitimate medical explanations, such as a valid prescription. The MRO will then verify the prescription with the pharmacy or prescribing physician to ensure its legitimacy. If a valid prescription is confirmed, the MRO can then report the result as negative to the employer, protecting the individual’s privacy while ensuring an accurate outcome.