Most Commonly Prescribed Psychiatric Medications: Hydroxyzine/Vistaril
Dr. G
Hydroxyzine is a medication I’m very familiar with, it’s used as an as needed medication for anxiety and insomnia on my inpatient unit.
Hydroxyzine is a histamine receptor antagonist or antihistamine with anticholinergic properties like diphenhydramine.
It’s FDA approved for several things, but my favorite is anxiety and tension associated with psychoneurosis. Several other indications include anxiety associated with organic disease states, premedication sedation, and anxiety withdrawal symptoms in alcohol use disorder.
The mechanism is very simple it blocks histamine H1 receptors, not much else to say about it.
The usual dosing for anxiety is 50-100 mg 4 times per day according to the FDA, but I would use caution with the dosing because in 2015 the European Medicines Agency announced a small but definite risk for QT interval prolongation and torsade de pointes in persons using hydroxyzine. It’s best to keep adult doses at 100 mg/day or less and 2 mg/kg/day in children weighing up to 40 kg.
If possible, avoid hydroxyzine in the elderly or limit the dose to 50 mg/day
For dosing be sure to use hydroxyzine in the lowest effective dose, avoid it in patients with known risk factors for cardiac arrhythmias or on medications that can increase the risk of QT prolongation.
The anticholinergic activity of hydroxyzine is much lower than that of diphenhydramine, it’s more selective for the histamine receptors. There can still be some risk of cognitive impairment due to anticholinergic activity.
Hydroxyzine is highly lipophilic and easily crosses the blood-brain-barrier.
The half-life is around 24 hours
Other common side effects include sedation, dry mouth, and tremor
Hydroxyzine is contraindicated in early pregnancy and not recommended for breast feeding mothers.
To sum things up, this medication offers an option for the short-term treatment of anxiety that is not addictive. It still has some risks and like most medications that target anxiety is not meant for long term management.
