From the Research
Hydroxyzine typically takes around 4-5 days to be completely eliminated from the body, considering its half-life and the time it takes for the drug to be fully cleared from the system. The medication has a half-life of approximately 20 hours in adults, as reported in studies such as 1, meaning it takes this amount of time for half of the drug to be cleared from your system. Generally, a drug is considered fully eliminated after 4-5 half-lives, which equals roughly 3-4 days for hydroxyzine, but this can extend to 7 days in some individuals due to various factors. Some key factors that affect elimination time include:
- Age: Elderly patients may experience longer elimination times
- Liver function: Impaired liver function can lead to slower elimination of hydroxyzine, as seen in patients with primary biliary cirrhosis 2
- Kidney function: Renal impairment can also affect the elimination of hydroxyzine
- Individual metabolism: Variations in metabolic rates among individuals can influence how quickly hydroxyzine is eliminated from the body This extended presence in the body explains why hydroxyzine's anti-anxiety and antihistamine effects can last for several days after discontinuation. If you're concerned about hydroxyzine showing up on a drug test, most standard screenings don't test for it, though specialized tests could detect it within this elimination window. It's also worth noting that hydroxyzine's pharmacokinetics can vary, with a mean serum elimination half-life of 36.6 hours reported in patients with primary biliary cirrhosis 2, highlighting the importance of considering individual patient factors when assessing elimination times.