Table of ContentsView AllTable of ContentsHow Long Does Hydroxyzine Last?Common DosagesSide EffectsAlternativesFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
How Long Does Hydroxyzine Last?
Common Dosages
Side Effects
Alternatives
Frequently Asked Questions
Hydroxyzineis a generic prescription medication that is available in two formulations:
Hydroxyzine is anantihistamineused to treat various conditions, such as the following:
Many people who take hydroxyzine wonder how long each dose lasts. This article will answer that question and provide other information about this medication.
Hydroxyzine hydrochloride (HCL) and hydroxyzine pamoate are both considered to be equal in terms of dosage and how they are absorbed.
A dose of the medication starts to work as soon as 15 to 60 minutes and lasts up to four to six hours.One clinical study found that a dose of hydroxyzine reaches its maximum effect in about two hours.
A medication’s half-life is when it takes about half of the medication to leave the body. It takes about five half-lives for a medication dose to leave the body.The half-life of both forms of hydroxyzine ranges from 14 to 25 hours.Thus, the medication can remain in the body for about 70 to 125 hours (five half-lives) after the last dose.
However, the effects of a dose may only last up to about six hours. If you keep taking doses of hydroxyzine as prescribed (usually every six to eight hours), some medicine will remain in your system until 70 to 125 hours after you take the last dose.
The prescribing information also notes that hydroxyzine can suppress inflammation anditchingfor up to four days.
How Long Does Hydroxyzine Last - SummaryThe numbers above can be confusing, so here is a quick summary: A dose of hydroxyzine can start working within 15 to 60 minutesand reaches its maximum effect in about two hours.The effects of a dose wear off after about six hours, and the medicine may be prescribed to be taken several times daily. However, the medicine does not completely leave your body for up to 125 hours (five days) after the last dose is taken.
How Long Does Hydroxyzine Last - Summary
The numbers above can be confusing, so here is a quick summary: A dose of hydroxyzine can start working within 15 to 60 minutesand reaches its maximum effect in about two hours.The effects of a dose wear off after about six hours, and the medicine may be prescribed to be taken several times daily. However, the medicine does not completely leave your body for up to 125 hours (five days) after the last dose is taken.
What Are Common Dosages of Hydroxyzine?
Hydroxyzine is available in the following forms:
Common dosages include the following:
Some healthcare providers prescribe hydroxyzineoff-label. Off-label prescribing is when a healthcare provider prescribes a medication for a use that the Food and Drug Administration (FDA) has not approved. However, research shows the medication may help certain conditions.
Pouring prescription medicine into hand.Filmstax / Getty Images
Filmstax / Getty Images
What Are the Side Effects of Hydroxyzine?
Hydroxyzine is a first-generation antihistamine. These “older” antihistamines cross theblood-brain barrier. This causes side effects (such as drowsiness and impaired coordination) even at normal doses. These side effects can be troublesome in some people, like older adults or those with certain medical conditions.
Common side effects of hydroxyzine may include, but are not limited to, the following:
Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you have a medical emergency.
Serious side effects and their symptoms can include the following:
Report Side Effects
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Who Should Not Take Hydroxyzine?
Hydroxyzine is not appropriate for everyone. Before taking hydroxyzine, tell your healthcare provider about your:
You should not take this medication if you areallergicto hydroxyzine or any of the inactive ingredients in hydroxyzine.
You shouldnottake hydroxyzine if you areallergic to the following medicationsbecause hydroxyzine breaks down in the body into the following products:
People withlong QT syndromealso shouldnottake hydroxyzine.
In some people, hydroxyzine may beprescribed with cautiononly if the healthcare provider determines it is safe. Some examples include the following:
What Are Interactions With Hydroxyzine?
Tell your healthcare provider about all your medicines, including prescription and over-the-counter (OTC) medicines, vitamins, and supplements.
While taking hydroxyzine, do not start any new medications without approval from your healthcare provider.
Food and drink interactions include the following:
Somedrug interactionsinclude, but are not limited to:
Because many interactions can potentially occur with hydroxyzine, talking to your healthcare provider about drug interactions is essential.
Drug InteractionsThis is not a full list of drug interactions. Other drug interactions may occur with hydroxyzine. Consult your healthcare provider for more information about drug interactions and how they may affect you.
Drug Interactions
This is not a full list of drug interactions. Other drug interactions may occur with hydroxyzine. Consult your healthcare provider for more information about drug interactions and how they may affect you.
Hydroxyzine Alternatives
Sometimes, hydroxyzine is not a first-choice or appropriate drug in some people. For example, as a first-generation antihistamine, it causes many side effects.
Newer antihistamines likeAllegra (fexofenadine)and Xyzal (levocetirizine) may still cause some drowsiness, however, not to the extent of first-generation antihistamines. And these newer antihistamines cause fewer side effects in general.
Also, hydroxyzine may cause more side effects and not be appropriate in older adults. This is due to the potential increased risk of the following:
These can even occur in younger adults as well. Therefore, for many people, hydroxyzine may not be the best choice of medication. Another medication may be considered.
Let’s talk more about other options for insomnia and allergies.
What Are the Alternatives for Insomnia?
If you have trouble falling asleep and/or staying asleep, there are other options you can try. For example:
What Are the Alternatives for Allergies?
If you have allergies, you can see an allergist who can help you identify your triggers and find ways to avoid them. Some tips include the following:
There are many other approaches available to treat allergy symptoms, including the following:
You can ask your healthcare provider or pharmacist which medicine or combination of medicines would be best for you based on your symptoms and other medical conditions you have.
Summary
Hydroxyzine is a medication used to treat insomnia, anxiety, and itching.
A dose of hydroxyzine may start working as quickly as 15 to 60 minutes.
It reaches the maximum effect in about two hours.
Due to its long half-life, hydroxyzine can stay in your body for up to 125 hours after the last dose.
Because it causes sedation and many other side effects, hydroxyzine is not always the first choice of drug.
As always, it is best to discuss your medical care with your healthcare provider, who can give you personalized medical advice based on your medical history.
Frequently Asked QuestionsA dose of hydroxyzine can start working within an hour and reaches its maximum effect in about two hours. The way it is dosed depends on the person’s age and symptoms. Although it can last a long time until it completely leaves the body, its effects wear off after about six hours, and the medicine can be dosed up to three or four times daily, depending on the individual.Hydroxyzine is generally dosed up to four times daily as needed for anxiety. It can start working within an hour, and it reaches its maximum effect in about two hours, but the effects may wear off after about six hours, even though the medication takes much longer to clear the body completely. Your healthcare provider can determine the appropriate dosing.Learn MoreSevere Anxiety: Symptoms, Types, Causes, TreatmentHydroxyzine is not a controlled substance. It does not have a risk for abuse and dependence.Learn MoreDrug Addiction Effects: Physical and Mental Symptoms
A dose of hydroxyzine can start working within an hour and reaches its maximum effect in about two hours. The way it is dosed depends on the person’s age and symptoms. Although it can last a long time until it completely leaves the body, its effects wear off after about six hours, and the medicine can be dosed up to three or four times daily, depending on the individual.
Hydroxyzine is generally dosed up to four times daily as needed for anxiety. It can start working within an hour, and it reaches its maximum effect in about two hours, but the effects may wear off after about six hours, even though the medication takes much longer to clear the body completely. Your healthcare provider can determine the appropriate dosing.Learn MoreSevere Anxiety: Symptoms, Types, Causes, Treatment
Hydroxyzine is generally dosed up to four times daily as needed for anxiety. It can start working within an hour, and it reaches its maximum effect in about two hours, but the effects may wear off after about six hours, even though the medication takes much longer to clear the body completely. Your healthcare provider can determine the appropriate dosing.
Learn MoreSevere Anxiety: Symptoms, Types, Causes, Treatment
Hydroxyzine is not a controlled substance. It does not have a risk for abuse and dependence.Learn MoreDrug Addiction Effects: Physical and Mental Symptoms
Hydroxyzine is not a controlled substance. It does not have a risk for abuse and dependence.
Learn MoreDrug Addiction Effects: Physical and Mental Symptoms
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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Epocrates.Atarax.Epocrates.Vistaril.U.S. National Library of Medicine.Hydroxyzine pamoate capsule.U.S. National Library of Medicine.Hydroxyzine HCL tablet, hydroxyzine HCL tablet, film coated, hydroxyzine hydrochloride tablet, film coated.Prescribers’ Digital Reference.Hydroxyzine pamoate - drug summary.Prescribers’ Digital Reference.Hydroxyzine hydrochloride - drug summary.Simons ER, Simons KJ, Frith EM.The pharmacokinetics and antihistaminic of the H1 receptor antagonist hydroxyzine.J Allergy Clin Immunol. 1984;73(1, Part 1):69-75. doi:10.1016/0091-6749(84)90486-XScience Direct.Drug half life.Burgazli CR, Rana KB, Brown JN, et al.Efficacy and safety of hydroxyzine for sleep in adults: systematic review.Hum Psychopharmacol Clin Exp. 2023;38(2):e2864. doi:10.1002/hup.2864Schaaf L, Hendeles L, Weinberger M.Suppression of seasonal allergic rhinitis symptoms with daily hydroxyzine. JAllergy Clin Immunol. 1979;63(2):129-33. doi: 10.1016/0091-6749(79)90203-3Simons FE, Simons KJ.H1 antihistamines: current status and future directions.World Allergy Organ J. 2008;1(9):145-155. doi:10.1186/1939-4551-1-9-145Snowman AM, Snyder SH.Cetirizine: actions on neurotransmitter receptors.J Allergy Clin Immunol. 1990;86(6 Pt 2):1025-1028. doi:10.1016/s0091-6749(05)80248-9Epocrates.Hydroxyzine.2023 American Geriatrics Society Beers Criteria Update Expert Panel.American Geriatrics Society 2023 updated AGS Beers Criteria® for potentially inappropriate medication use in older adults.Journal of the American Geriatrics Society.2023:1(7):2052-2081.National Heart, Lung, and Blood Institute.Insomnia treatment.American College of Allergy, Asthma & Immunology.Seasonal allergies.Asthma and Allergy Foundation of America.What are the best treatments for allergies?
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Epocrates.Atarax.
Epocrates.Vistaril.
U.S. National Library of Medicine.Hydroxyzine pamoate capsule.
U.S. National Library of Medicine.Hydroxyzine HCL tablet, hydroxyzine HCL tablet, film coated, hydroxyzine hydrochloride tablet, film coated.
Prescribers’ Digital Reference.Hydroxyzine pamoate - drug summary.
Prescribers’ Digital Reference.Hydroxyzine hydrochloride - drug summary.
Simons ER, Simons KJ, Frith EM.The pharmacokinetics and antihistaminic of the H1 receptor antagonist hydroxyzine.J Allergy Clin Immunol. 1984;73(1, Part 1):69-75. doi:10.1016/0091-6749(84)90486-X
Science Direct.Drug half life.
Burgazli CR, Rana KB, Brown JN, et al.Efficacy and safety of hydroxyzine for sleep in adults: systematic review.Hum Psychopharmacol Clin Exp. 2023;38(2):e2864. doi:10.1002/hup.2864
Schaaf L, Hendeles L, Weinberger M.Suppression of seasonal allergic rhinitis symptoms with daily hydroxyzine. JAllergy Clin Immunol. 1979;63(2):129-33. doi: 10.1016/0091-6749(79)90203-3
Simons FE, Simons KJ.H1 antihistamines: current status and future directions.World Allergy Organ J. 2008;1(9):145-155. doi:10.1186/1939-4551-1-9-145
Snowman AM, Snyder SH.Cetirizine: actions on neurotransmitter receptors.J Allergy Clin Immunol. 1990;86(6 Pt 2):1025-1028. doi:10.1016/s0091-6749(05)80248-9
Epocrates.Hydroxyzine.
2023 American Geriatrics Society Beers Criteria Update Expert Panel.American Geriatrics Society 2023 updated AGS Beers Criteria® for potentially inappropriate medication use in older adults.Journal of the American Geriatrics Society.2023:1(7):2052-2081.
National Heart, Lung, and Blood Institute.Insomnia treatment.
American College of Allergy, Asthma & Immunology.Seasonal allergies.
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