Hydroxyzine Pamoate 50mg Capsules
It is used to treat itching.It is used to treat anxiety.It is used to put you to sleep for surgery.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antihistamine, Anxiolytic, Sedative/Hypnotic
Pharmacologic Class
First-generation H1-receptor antagonist
Pregnancy Category
C
FDA Approved
Jan 1956
DEA Schedule
Not Controlled
Overview
What is this medicine?
Hydroxyzine is an antihistamine that can help reduce anxiety, relieve itching from allergies, and cause drowsiness to help with sleep before medical procedures. It works by blocking a natural substance (histamine) that your body makes.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but if it causes stomach upset, take it with food.
Storing and Disposing of Your Medication
Store this medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but if it causes stomach upset, take it with food.
Storing and Disposing of Your Medication
Store this medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid alcohol and other CNS depressants (e.g., sleeping pills, pain medications) as they can increase drowsiness and dizziness.
- Do not drive or operate heavy machinery until you know how this medication affects you, as it can cause significant drowsiness.
- To relieve dry mouth, suck on sugarless candy or ice chips, or use artificial saliva.
- Drink plenty of fluids to help with dry mouth and constipation.
- Avoid grapefruit juice as it may interact with the medication (though interaction is minor).
Available Forms & Alternatives
Available Strengths:
- Hydroxyzine Pamoate 100mg Capsules
- Hydroxyzine 10mg/5ml Syrup
- Hydroxyzine 50mg/ml Inj, 1ml
- Hydroxyzine Hcl 50mg/ml For Inj
- Hydroxyzine Hcl 25mg/ml Inj 1ml
- Hydroxyzine Hcl 25mg Tabs (white)
- Hydroxyzine Hcl 50mg Tabs (white)
- Hydroxyzine Hcl 10mg Tablets
- Hydroxyzine Pamoate 25mg Capsules
- Hydroxyzine 10mg/5ml Syrup
- Hydroxyzine Pamoate 50mg Capsules
- Hydroxyzine Pamoate 25mg Capsules
- Hydroxyzine Hcl 25mg Tabs
- Hydroxyzine Pamoate 50mg Capsules
Dosing & Administration
Adult Dosing
Standard Dose:
For anxiety: 50-100 mg 3-4 times daily. For pruritus: 25 mg 3-4 times daily. For sedation (pre-op): 50-100 mg single dose.
Dose Range:
25 - 400 mg
Condition-Specific Dosing:
anxiety:
50-100 mg 3-4 times daily
pruritus:
25 mg 3-4 times daily
preoperative_sedation:
50-100 mg single dose
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established (generally avoided in infants <6 months)
Child:
For pruritus: 0.5-1 mg/kg/day in divided doses (e.g., 0.6 mg/kg/day). For pre-op sedation: 0.6 mg/kg single dose.
Adolescent:
Similar to adult dosing, but start with lower doses (e.g., 25 mg 3-4 times daily for pruritus) and titrate as needed.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment usually needed, monitor for increased sedation.
Moderate:
Consider 50% dose reduction.
Severe:
Consider 50% dose reduction and extend dosing interval.
Dialysis:
Hydroxyzine is not significantly removed by dialysis. Administer after dialysis; consider dose reduction.
Hepatic Impairment:
Mild:
No specific adjustment usually needed, monitor for increased sedation.
Moderate:
Consider 50% dose reduction.
Severe:
Consider 50% dose reduction and extend dosing interval.
Pharmacology
Mechanism of Action
Hydroxyzine is a first-generation antihistamine that acts as a potent H1-receptor antagonist. Its anxiolytic, sedative, and antiemetic effects are primarily due to its central nervous system (CNS) depressant activity, which is thought to be related to its anticholinergic and anti-serotonergic properties, as well as its ability to suppress activity in subcortical areas of the CNS, including the limbic system and reticular formation.
Pharmacokinetics
Absorption:
Bioavailability:
Not available (well absorbed)
Tmax:
2-4 hours
FoodEffect:
Food may delay Tmax but does not significantly affect AUC.
Distribution:
Vd:
16 L/kg (large volume of distribution)
ProteinBinding:
Approximately 93% (Hydroxyzine), 96% (Cetirizine)
CnssPenetration:
Yes
Elimination:
HalfLife:
Hydroxyzine: 7-20 hours (highly variable, longer in elderly and impaired renal/hepatic function); Cetirizine: 8-10 hours
Clearance:
Not available (primarily hepatic metabolism)
ExcretionRoute:
Primarily renal (as metabolites)
Unchanged:
<1% (Hydroxyzine)
Pharmacodynamics
OnsetOfAction:
15-30 minutes
PeakEffect:
2-4 hours
DurationOfAction:
4-6 hours (sedation), up to 24 hours (antihistaminic effects)
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Abnormal or rapid heartbeat
Severe dizziness or fainting
Difficulty controlling body movements
Confusion
A rare but serious skin reaction, characterized by:
+ Fever
+ Multiple small skin spots within large areas of redness and swelling
If you experience a rash or any of these symptoms, contact your doctor immediately.
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor or seek medical help:
Dry mouth
Drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Abnormal or rapid heartbeat
Severe dizziness or fainting
Difficulty controlling body movements
Confusion
A rare but serious skin reaction, characterized by:
+ Fever
+ Multiple small skin spots within large areas of redness and swelling
If you experience a rash or any of these symptoms, contact your doctor immediately.
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor or seek medical help:
Dry mouth
Drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe drowsiness or dizziness
- Difficulty urinating
- Blurred vision or eye pain
- Severe dry mouth or constipation
- Confusion or hallucinations
- Tremors or uncontrolled muscle movements
- Fast, pounding, or irregular heartbeat (palpitations)
- Fainting or severe lightheadedness
- Skin rash or hives (signs of allergic reaction)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction and its symptoms.
A history of prolonged QT interval on an electrocardiogram (ECG).
If you are in early pregnancy, as this medication should not be taken during this time.
If you are breastfeeding, as you should not breastfeed while taking this medication.
Additionally, this medication may interact with other medications or health conditions. Therefore, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter medications you are taking.
Any natural products or vitamins you are using.
* Your health problems, including any medical conditions or concerns.
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. This will help determine whether it is safe for you to take this medication with your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction and its symptoms.
A history of prolonged QT interval on an electrocardiogram (ECG).
If you are in early pregnancy, as this medication should not be taken during this time.
If you are breastfeeding, as you should not breastfeed while taking this medication.
Additionally, this medication may interact with other medications or health conditions. Therefore, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter medications you are taking.
Any natural products or vitamins you are using.
* Your health problems, including any medical conditions or concerns.
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. This will help determine whether it is safe for you to take this medication with your other medications and health conditions.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Before engaging in activities that require alertness, such as driving, wait until you understand how this drug affects you. Consult your doctor before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions.
This medication has been associated with an abnormal and potentially life-threatening heart rhythm, known as a prolonged QT interval on an electrocardiogram (ECG), which may increase the risk of sudden death. Discuss this risk with your doctor.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects.
If you are pregnant or planning to become pregnant, notify your doctor. You and your doctor will need to discuss the potential benefits and risks of using this medication during pregnancy.
This medication has been associated with an abnormal and potentially life-threatening heart rhythm, known as a prolonged QT interval on an electrocardiogram (ECG), which may increase the risk of sudden death. Discuss this risk with your doctor.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects.
If you are pregnant or planning to become pregnant, notify your doctor. You and your doctor will need to discuss the potential benefits and risks of using this medication during pregnancy.
Overdose Information
Overdose Symptoms:
- Severe sedation or coma
- Confusion
- Hallucinations
- Seizures
- Severe anticholinergic effects (e.g., severe dry mouth, dilated pupils, flushed skin, hyperthermia, urinary retention, decreased bowel sounds)
- Cardiac arrhythmias (e.g., QT prolongation, Torsade de Pointes)
- Respiratory depression
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and symptomatic, including gastric lavage, activated charcoal, and monitoring of vital signs and ECG. Physostigmine may be considered for severe anticholinergic symptoms, but use with caution due to potential for cardiac effects.
Drug Interactions
Contraindicated Interactions
- QT-prolonging drugs (e.g., Class IA and III antiarrhythmics, certain antipsychotics, macrolide antibiotics, fluoroquinolone antibiotics, methadone, ondansetron)
- Other drugs that cause Torsade de Pointes
Major Interactions
- CNS depressants (e.g., alcohol, benzodiazepines, opioids, barbiturates, other sedatives, hypnotics, tricyclic antidepressants) - additive CNS depression
- Anticholinergic drugs (e.g., tricyclic antidepressants, atropine, benztropine, other first-generation antihistamines) - additive anticholinergic effects
- Cholinesterase inhibitors (e.g., donepezil, rivastigmine) - hydroxyzine may antagonize their effects
Moderate Interactions
- Monoamine Oxidase Inhibitors (MAOIs) - may prolong and intensify anticholinergic and CNS depressant effects
- Beta-blockers (e.g., metoprolol, propranolol) - may increase hydroxyzine levels (minor interaction)
Minor Interactions
- Not available (most interactions are significant due to additive effects)
Monitoring
Baseline Monitoring
Patient history (cardiac conditions, electrolyte imbalances, family history of sudden cardiac death)
Rationale: To assess risk for QT prolongation and Torsade de Pointes.
Timing: Prior to initiation, especially if risk factors are present.
Renal and Hepatic function tests
Rationale: To guide initial dosing and identify need for dose adjustment in patients with impairment.
Timing: Prior to initiation in patients with suspected or known impairment.
Routine Monitoring
Sedation level/Mental status
Frequency: Daily, or as needed based on patient response
Target: Desired level of sedation without excessive drowsiness or impairment.
Action Threshold: Excessive sedation, confusion, or paradoxical excitation; consider dose reduction or discontinuation.
Anticholinergic side effects (e.g., dry mouth, constipation, urinary retention, blurred vision)
Frequency: Daily, or as needed based on patient report
Target: Minimal to no anticholinergic symptoms.
Action Threshold: Significant or bothersome anticholinergic symptoms; consider dose reduction or alternative.
Cardiac rhythm (ECG)
Frequency: Not routinely required unless risk factors for QT prolongation are present or new cardiac symptoms develop.
Target: Normal QTc interval (<450 ms for men, <470 ms for women).
Action Threshold: Prolonged QTc interval (>500 ms or increase of >60 ms from baseline); discontinue hydroxyzine and investigate.
Symptom Monitoring
- Drowsiness
- Dizziness
- Dry mouth
- Constipation
- Urinary retention
- Blurred vision
- Confusion
- Paradoxical excitation (especially in children or elderly)
- Tremor
- Headache
- QT prolongation symptoms (palpitations, syncope, seizures - rare but serious)
Special Patient Groups
Pregnancy
Category C. Use during pregnancy is generally not recommended, especially during early pregnancy, due to potential for fetal harm (e.g., CNS depression, anticholinergic effects, and withdrawal symptoms in neonates if used near term). Weigh potential benefits against risks.
Trimester-Specific Risks:
First Trimester:
Potential for teratogenicity, though human data are limited and conflicting. Generally avoided.
Second Trimester:
Risk of CNS depression and anticholinergic effects in the fetus. Use only if clearly needed.
Third Trimester:
Risk of neonatal withdrawal symptoms (e.g., tremors, hypertonia) and respiratory depression if used near term. Avoid if possible.
Lactation
L4 (Potentially Hazardous). Hydroxyzine and its active metabolite, cetirizine, are excreted into breast milk. Use is generally not recommended due to potential for infant sedation, anticholinergic effects, and theoretical risk of decreased milk supply. Consider alternative agents or avoid breastfeeding.
Infant Risk:
Sedation, irritability, anticholinergic effects (e.g., dry mouth, constipation), and potential for decreased milk supply in the mother.
Pediatric Use
Use with caution, especially in very young children, due to increased susceptibility to paradoxical excitation or excessive sedation. Dosing is weight-based. Not recommended for infants under 6 months.
Geriatric Use
Start with lower doses (e.g., 25 mg daily or BID) due to increased sensitivity to anticholinergic effects (e.g., confusion, urinary retention, constipation) and CNS depression (e.g., sedation, dizziness, falls). Monitor closely for adverse effects. Consider Beers Criteria recommendations.
Clinical Information
Clinical Pearls
- Hydroxyzine pamoate (Vistaril) is often preferred over hydroxyzine HCl (Atarax) for its less bitter taste, though both are equally effective.
- Pamoate salt is absorbed more slowly than the HCl salt, which may lead to a slightly delayed onset of action but similar overall efficacy.
- Due to its sedative properties, hydroxyzine is often used at bedtime for anxiety or pruritus.
- Patients should be warned about the potential for significant drowsiness and impaired ability to perform tasks requiring mental alertness.
- Anticholinergic side effects are common, especially in the elderly. Advise patients on managing dry mouth and constipation.
- Avoid concomitant use with other QT-prolonging medications due to the risk of serious cardiac arrhythmias.
Alternative Therapies
- For anxiety: Buspirone, SSRIs/SNRIs, benzodiazepines (short-term)
- For pruritus: Second-generation antihistamines (e.g., cetirizine, loratadine, fexofenadine), topical corticosteroids
- For sedation: Diphenhydramine, zolpidem, melatonin
Cost & Coverage
Average Cost:
Variable, generally low per 30 capsules
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
General Drug Facts
If your symptoms or health condition do not improve or worsen over time, it is essential to contact your doctor for further evaluation and guidance. To ensure your safety and the effectiveness of your treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to consult with your pharmacist for more information. If you have any questions or concerns about your medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide detailed information about the overdose, including the name of the medication taken, the amount, and the time it occurred.