Hydroxyzine Pamoate and Vistaril: Same Medication, Different Salt Forms
Yes, hydroxyzine pamoate is essentially the same medication as Vistaril—Vistaril is simply a brand name for hydroxyzine pamoate. 1
Understanding the Formulations
Hydroxyzine exists in two salt forms that are therapeutically equivalent but differ in their chemical composition:
- Hydroxyzine pamoate is the salt form marketed under the brand name Vistaril 2
- Hydroxyzine hydrochloride is the alternative salt form, which has the chemical name (±)-2-[2-[4-(p-Chloro-α-phenylbenzyl)-1-piperazinyl]ethoxy]ethanol dihydrochloride 1
Both formulations work identically as first-generation H1 antihistamines with sedating properties 3.
Clinical Equivalence
The two salt forms are clinically interchangeable and produce the same therapeutic effects:
- Both are rapidly absorbed from the gastrointestinal tract with clinical effects noted within 15-30 minutes after oral administration 1
- Both function as H1-receptor antagonists with antihistaminic, anxiolytic, antiemetic, and sedative properties 1
- Both are classified as first-generation antihistamines associated with sedation, impaired driving ability, and cognitive decline, particularly in elderly patients 3
Practical Prescribing Considerations
When prescribing or dispensing, be aware that:
- Vistaril specifically refers to the pamoate salt formulation 2
- Generic hydroxyzine tablets typically contain hydroxyzine hydrochloride 1
- Dosing ranges are identical (10-50 mg for anxiety and urticaria) regardless of which salt form is used 4, 5
Important Safety Note
Regardless of whether you're using hydroxyzine pamoate (Vistaril) or hydroxyzine hydrochloride, the same safety considerations apply:
- Contraindicated in early pregnancy 5
- Dose reduction required in moderate renal impairment (creatinine clearance 10-20 mL/min) 5
- Avoid entirely in severe renal impairment and severe liver disease 5
- Significant sedation and driving impairment can occur, with drivers in fatal accidents being 1.5 times more likely to be taking first-generation antihistamines like hydroxyzine 4
- Elderly patients require lower starting doses and close monitoring for confusion, over-sedation, and fall risk 5