Vistaril Half-Life – Will It Show Up On A Drug Test?

Last Updated: March 11, 2020

Hydroxyzine is a popular drug for anxiety treatment, but users are concerned about Vistaril showing up on a drug test. There are also concerns about Vistaril false-positive for benzos on a drug test.

Can Vistaril show up on a drug test? What is the half-life of Vistaril? Does drug test search for Hydroxyzine?

Hydroxyzine Half-Life

Generally, hydroxyzine stays in the system, on average, two days. The half-life of a drug varies between the age groups:

  • Adults – 20 hours
  • Elderly – 29 hours
  • Children(14 years and above) – 11-14 hours.

The duration of the drug’s stay in the body depends on several factors:

  • Time of the last dose
  • Route of administration
  • Metabolic rate
  • Genetic
  • Individual differences in pharmacokinetics

The route of administration also plays a role. For injections, Vistaril’s concentration level in the body is usually at its peak after 5-10 minutes of use, while it takes 30-45 minutes with tablets. So, can one snort hydroxyzine? Yes, sniffing is possible, and the timing for peak concentration is the same as with tablets.

Woman Takes Medicine And Holds Glass Of Water

Hydroxyzine Detection Window

The detection window for hydroxyzine varies between the urine, blood, saliva, and hair. These detection time frames may vary between patients.

  • Blood Test: Blood drug test is very accurate; however, it is an expensive one. The detection period for Atarax using blood tests is up to 27 hours.
  • Urine Test: A urine drug test can be done to detect the presence of hydroxyzine. It is normally done by collecting a 30-60 mL urine sample of a patient and then evaluated in the laboratory. The detection window in the urine is up to 24 hours.
  • Saliva Test: Saliva test is one of Vistaril drug test methods with the shortest detection window. The detection window of hydroxyzine in the saliva is 8 hours. If tests are not carried out within 8 hours after use, traces of Vistaril will not be detected.
  • Hair Test: The detection period for hair tests is considered the longest. With the use of hair shafts, traces of Atarax consumed over a long period can be detected. The detection period in the hair is up to one month and remains detected for as long three months, depending on the length of the hair shaft.

Factors That Influence Hydroxyzine Detection Time


Hydroxyzine exists in different doses; 10mg, 25mg, 50mg, 100mg. For instance, one can be prescribed Vistaril 25 mg for anxiety. It is a moderate dose that will leave the body in 20 hours. At the same time, consuming high doses of hydroxyzine (100 mg and more) makes it tough for the body to flush it out of the system.


Dehydration leads to an increased concentration of hydroxyzine in the body. Since there is a low level of water in the system, dehydration can prolong the detection window considerably. In this case, Vistaril on a drug test can (with low probability) cause a false-positive result.

Length Of Use

Patients who have used Vistaril for an extended period of time, it becomes very difficult for the body to eliminate it. This leads to a longer detection window in the body. It is important to note that hydroxyzine does not show up on a drug screen. Its presence is only noticeable if a test is carried out specifically.


The basal metabolic rate determines how long Atarax stays in one’s system, especially the saliva. Hydroxyzine’s detection window is shorter for people with high BMRs, as they tend to excrete Atarax from their bodies faster.

Patient Receives Medical Consultation

False-Positive Test For Benzos

Most people are concerned whether or not a standard drug test would have false-positive results for benzos if one is using hydroxyzine. The possibilities of achieving Vistaril false positive for benzo are very low. This is due to differences in their mechanism of action and chemical structure.

So, does Vistaril show up on a drug test? No. It doesn’t. Even in high doses, it is very unlikely that hydroxyzine shows up in any standard drug test. Since hydroxyzine is not exactly a common and addictive drug, most standard drug tests are not designed to detect its presence.

Always Follow The Doctor’s Prescription

Even though hydroxyzine is not seen as an addictive drug capable of causing serious harm, there have been rare cases of severe side effects in patients who use it. Therefore it is advisable that patients always follow the doctor’s prescription, to prevent overdosing and avoid dangerous interactions. Those addicted to hydroxyzine should seek treatment in an addiction treatment facility is the way to go. With the help of professionals and carefully designed treatment programs for addicts, the patient will be able to break the addiction cycle and get back to a normal life.

Page Sources

  1. Nancy C. Brahm, Pharm.D., M.S., Lynn L. Yeager, M.L.I.S., Mark D. Fox, M.D., Ph.D., M.P.H., Kevin C. Farmer, Ph.D., Tony A. Palmer, B.S.Pharm., M.B.A., Commonly prescribed medications and potential false-positive urine drug screens, American Journal of Health-System Pharmacy, Volume 67, Issue 16, 15 August 2010, Pages 1344–1350,
  2. Algren, D. A., & Christian, M. R. (2015). Buyer Beware: Pitfalls in Toxicology Laboratory Testing. Missouri medicine, 112(3), 206–210.

Published on: March 11th, 2020

Updated on: March 11th, 2020


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