Hydroxyzine Pamoate 25mg 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
Category C
FDA Approved
Jan 1970
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 you relax before a procedure or sleep. 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. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store this medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets. When you're finished with the medication or it expires, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of unused or expired medication, and ask about potential drug take-back programs in your area.
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 regular 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. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store this medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets. When you're finished with the medication or it expires, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of unused or expired medication, and ask about potential drug take-back programs in your area.
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 regular 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 medications that cause drowsiness, as this can worsen side effects.
- Be cautious when driving or operating machinery until you know how this medication affects you.
- Avoid grapefruit juice as it may increase levels of hydroxyzine.
- Stay hydrated to help with dry mouth.
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 orally 4 times daily. For pruritus: 25 mg orally 3-4 times daily. For sedation (pre-operative/post-operative): 50-100 mg orally as a single dose.
Dose Range:
25 - 400 mg
Condition-Specific Dosing:
anxiety:
50-100 mg orally 4 times daily
pruritus:
25 mg orally 3-4 times daily
sedation:
50-100 mg orally as a single dose
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established (generally not recommended under 6 months)
Child:
For pruritus: 0.6 mg/kg/day to 1.2 mg/kg/day orally in divided doses (e.g., 2 mg/kg/day in 3-4 divided doses for children >6 years). For sedation: 0.6 mg/kg orally as a single dose.
Adolescent:
For pruritus: 25 mg orally 3-4 times daily. For anxiety: 50-100 mg orally 4 times daily (similar to adult dosing, adjusted for weight/response).
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, but monitor for increased sedation.
Moderate:
Consider dose reduction (e.g., 50% of usual dose) and extend dosing interval.
Severe:
Consider dose reduction (e.g., 50% of usual dose) and extend dosing interval. Avoid if possible due to accumulation of active metabolite (cetirizine).
Dialysis:
Hydroxyzine is not significantly dialyzable. Dose adjustment needed, monitor for adverse effects.
Hepatic Impairment:
Mild:
No specific adjustment recommended, but monitor for increased sedation.
Moderate:
Consider dose reduction (e.g., 50% of usual dose) and extend dosing interval.
Severe:
Consider dose reduction (e.g., 50% of usual dose) and extend dosing interval. Avoid if possible due to impaired metabolism.
Pharmacology
Mechanism of Action
Hydroxyzine is a first-generation antihistamine that acts as a potent H1-receptor antagonist in the periphery and central nervous system. Its anxiolytic and sedative effects are attributed to its activity on subcortical areas of the central nervous system, including the limbic system and reticular formation. It also possesses anticholinergic, antiemetic, and antispasmodic properties.
Pharmacokinetics
Absorption:
Bioavailability:
Well absorbed orally, approximately 80% for hydroxyzine HCl (pamoate salt is also well absorbed but may have slightly delayed absorption).
Tmax:
Hydroxyzine HCl: 1-2 hours. Hydroxyzine Pamoate: 2-4 hours.
FoodEffect:
Food may slightly delay absorption but does not significantly affect the extent of absorption.
Distribution:
Vd:
Approximately 16 L/kg (large volume of distribution, indicating extensive tissue distribution).
ProteinBinding:
Approximately 93% (primarily to alpha-1-acid glycoprotein).
CnssPenetration:
Yes (readily crosses the blood-brain barrier, contributing to its sedative effects).
Elimination:
HalfLife:
Hydroxyzine: Approximately 7-20 hours (highly variable, longer in elderly and those with renal/hepatic impairment). Cetirizine: Approximately 8-10 hours.
Clearance:
Not available (highly variable due to extensive metabolism).
ExcretionRoute:
Primarily renal (via urine) as metabolites, with a small amount of unchanged drug. Cetirizine is primarily excreted unchanged in urine.
Unchanged:
Less than 1% of hydroxyzine is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
15-30 minutes (for sedative/anxiolytic effects)
PeakEffect:
1-2 hours
DurationOfAction:
4-6 hours (for sedative/anxiolytic effects), up to 24 hours for antihistaminic effects due to cetirizine metabolite.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
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 heartbeat or fast heart rate
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 develop a rash or any of these symptoms, contact your doctor right away.
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Dry mouth
Drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult 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, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
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 heartbeat or fast heart rate
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 develop a rash or any of these symptoms, contact your doctor right away.
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Dry mouth
Drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult 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
- Fast, pounding, or irregular heartbeat (palpitations)
- Muscle tremors or uncontrolled movements
- Confusion or hallucinations
- Severe skin rash or swelling
- Seizures
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, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
A history of prolonged QT interval on an electrocardiogram (ECG).
If you are in the early stages of pregnancy. Note that this medication should not be taken during early pregnancy.
If you are breastfeeding. You should not breastfeed while taking this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist. They will help determine whether it is safe to take this medication in combination with your other medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting 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, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
A history of prolonged QT interval on an electrocardiogram (ECG).
If you are in the early stages of pregnancy. Note that this medication should not be taken during early pregnancy.
If you are breastfeeding. You should not breastfeed while taking this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist. They will help determine whether it is safe to take this medication in combination with your other medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Until you understand how this drug affects you, avoid operating a vehicle or engaging in any activities that require your full attention. Before consuming alcohol, using marijuana or other cannabis products, or taking any prescription or over-the-counter medications that may cause drowsiness, consult with your doctor.
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 experiencing 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.
Until you understand how this drug affects you, avoid operating a vehicle or engaging in any activities that require your full attention. Before consuming alcohol, using marijuana or other cannabis products, or taking any prescription or over-the-counter medications that may cause drowsiness, consult with your doctor.
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 experiencing 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
- Stupor or coma
- Hypotension
- Tachycardia
- QT prolongation
- Arrhythmias (including Torsade de Pointes)
- Respiratory depression
- Seizures
- Severe anticholinergic effects (e.g., severe dry mouth, dilated pupils, urinary retention, bowel obstruction)
What to Do:
Call 911 or Poison Control immediately (1-800-222-1222). Treatment is supportive and symptomatic. Gastric lavage may be considered if ingestion is recent. Activated charcoal may be administered. Monitor vital signs, ECG, and mental status. Avoid inducing emesis. Physostigmine may be considered for severe anticholinergic symptoms but carries risks.
Drug Interactions
Contraindicated Interactions
- Drugs that prolong the QT interval (e.g., Class IA and III antiarrhythmics, some antipsychotics, macrolide antibiotics, fluoroquinolones, certain antifungals, methadone, ondansetron, citalopram, escitalopram) due to risk of Torsade de Pointes.
- Patients with known acquired or congenital QT prolongation.
Major Interactions
- CNS depressants (e.g., alcohol, benzodiazepines, opioids, barbiturates, other sedatives/hypnotics, tricyclic antidepressants): Increased CNS depression.
- Anticholinergic drugs (e.g., atropine, tricyclic antidepressants, some antipsychotics, benztropine): Increased anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation).
- CYP3A4/5 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir, grapefruit juice): May increase hydroxyzine levels and risk of adverse effects.
- Beta-blockers (e.g., metoprolol, propranolol): May increase hydroxyzine levels due to shared metabolic pathways.
Moderate Interactions
- Monoamine Oxidase Inhibitors (MAOIs): May prolong and intensify anticholinergic and CNS depressant effects.
- Antihypertensives: May cause additive hypotensive effects.
- Cholinergic drugs (e.g., donepezil, rivastigmine): Hydroxyzine may antagonize their effects.
Minor Interactions
- Not available (most interactions are moderate to major due to CNS and anticholinergic effects).
Monitoring
Baseline Monitoring
Patient history (cardiac, renal, hepatic, seizure disorders)
Rationale: To identify contraindications, precautions, and risk factors for adverse effects (e.g., QT prolongation, excessive sedation).
Timing: Prior to initiation of therapy.
ECG (Electrocardiogram)
Rationale: To assess baseline QT interval, especially in patients with cardiac risk factors or those on other QT-prolonging drugs.
Timing: Prior to initiation, if clinically indicated.
Medication reconciliation
Rationale: To identify potential drug-drug interactions, especially with CNS depressants, anticholinergics, and QT-prolonging agents.
Timing: Prior to initiation of therapy.
Routine Monitoring
Level of sedation/alertness
Frequency: Daily, especially during initial therapy or dose adjustments.
Target: Appropriate for therapeutic goal (e.g., mild sedation for anxiety, deeper for pre-op).
Action Threshold: Excessive drowsiness, impaired coordination, or paradoxical excitation; consider dose reduction or discontinuation.
Anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation)
Frequency: Daily, especially in elderly or those on other anticholinergic drugs.
Target: Minimal to absent.
Action Threshold: Significant discomfort or functional impairment; consider dose reduction or alternative.
Cardiac rhythm (symptoms of palpitations, dizziness, syncope)
Frequency: As needed, if symptoms arise.
Target: Normal sinus rhythm.
Action Threshold: New onset of cardiac symptoms; consider ECG and discontinuation.
Symptom Monitoring
- Drowsiness
- Dizziness
- Dry mouth
- Blurred vision
- Urinary retention
- Constipation
- Headache
- Nervousness
- Tremor
- Palpitations
- Rash
- Paradoxical excitation (especially in children and elderly)
Special Patient Groups
Pregnancy
Generally not recommended during pregnancy, especially in the first trimester, due to potential for fetal harm (Category C). Use only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Limited human data, but animal studies show teratogenic effects at high doses. Avoid if possible.
Second Trimester:
Limited human data. Use with caution.
Third Trimester:
May cause CNS depression, hypotonia, and anticholinergic effects in the neonate if used close to delivery. Avoid if possible.
Lactation
Not recommended during breastfeeding (L3 - moderately safe, but potential for adverse effects). Hydroxyzine and its active metabolite, cetirizine, are excreted in breast milk. May cause sedation, irritability, or anticholinergic effects in the infant.
Infant Risk:
Moderate risk. Monitor infant for drowsiness, poor feeding, irritability, or anticholinergic effects. Consider alternative or temporary cessation of breastfeeding.
Pediatric Use
Use with caution, especially in infants and young children, due to increased susceptibility to CNS depression and paradoxical excitation. Dosing is weight-based. Not recommended for children under 6 months.
Geriatric Use
Use with extreme caution due to increased susceptibility to anticholinergic effects (e.g., confusion, urinary retention, constipation), sedation, and orthostatic hypotension. Start with lower doses (e.g., 10 mg 3-4 times daily or 25 mg at bedtime) and titrate slowly. The Beers Criteria recommend avoiding hydroxyzine in older adults due to its strong anticholinergic properties and risk of sedation.
Clinical Information
Clinical Pearls
- Hydroxyzine pamoate (Vistaril) is often preferred for anxiety due to its longer duration of action and less rapid onset compared to hydroxyzine HCl (Atarax), which is often used for pruritus or pre-op sedation.
- Due to its anticholinergic and sedative properties, hydroxyzine is generally not a first-line agent for chronic anxiety, especially in older adults.
- The active metabolite, cetirizine, contributes significantly to the antihistaminic effects and has a longer half-life, which can lead to prolonged effects.
- Educate patients about the risk of additive CNS depression with alcohol and other sedatives.
- Always assess for QT prolongation risk factors before initiating hydroxyzine, and avoid in patients with known QT prolongation or on other QT-prolonging drugs.
Alternative Therapies
- For anxiety: SSRIs (e.g., escitalopram, sertraline), SNRIs (e.g., venlafaxine, duloxetine), buspirone, benzodiazepines (short-term).
- For pruritus: Second-generation antihistamines (e.g., cetirizine, loratadine, fexofenadine), topical corticosteroids, doxepin (topical or oral).
- For sedation: Benzodiazepines (e.g., midazolam, lorazepam), zolpidem, melatonin.
Cost & Coverage
Average Cost:
$10 - $50 per 30 capsules (25mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (preferred generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.