What antihistamine (anti-histamine) is used to treat anxiety?

From the Guidelines

Hydroxyzine is the primary antihistamine used for anxiety treatment, as it is specifically approved for anxiolytic use in both Europe and the United States 1.

Key Points

• It's available in various forms, including Atarax and Vistaril, typically prescribed at doses of 25-100mg up to four times daily as needed.
• This medication works by blocking histamine receptors in the brain, which not only reduces allergic responses but also produces a calming effect on the central nervous system.
• Unlike benzodiazepines, hydroxyzine is not habit-forming, making it suitable for longer-term use 1.
• It's particularly helpful for patients with both anxiety and allergic conditions, or for those who need to avoid potentially addictive medications.
• Common side effects include drowsiness, dry mouth, and occasionally dizziness 1.
• The sedative effect typically begins within 30 minutes of taking the medication and can last for several hours.
• While other antihistamines like diphenhydramine (Benadryl) sometimes provide anxiety relief, hydroxyzine is specifically approved for anxiety management and generally considered more effective for this purpose 1.

Considerations

• First-generation antihistamines, including hydroxyzine, can cause sedative effects, performance impairment, and anticholinergic effects 1.
• However, hydroxyzine is a preferred option for anxiety treatment due to its specific approval and efficacy 1.
• Patients should be aware of the potential side effects and take necessary precautions to minimize risks 1.

From the FDA Drug Label

For symptomatic relief of anxiety and tension associated with psychoneurosis and as an adjunct in organic disease states in which anxiety is manifested. The antihistamine used for anxiety is hydroxyzine.

• It is used for the symptomatic relief of anxiety and tension associated with psychoneurosis.
• The effectiveness of hydroxyzine as an antianxiety agent for long term use (more than 4 months) has not been assessed by systematic clinical studies 2.

From the Research

Antihistamine Used for Anxiety

• Hydroxyzine is an antihistamine medication that has been used in the treatment of anxiety, as seen in studies 3, 4, 5.
• The efficacy of hydroxyzine in comparison with placebo or any other active agent in alleviating the acute symptoms of generalized anxiety disorder (GAD) has been investigated, with results showing that hydroxyzine is more effective than placebo for GAD 3.
• Hydroxyzine has been compared to other anxiolytic agents, such as benzodiazepines and buspirone, and has been found to be equivalent in terms of efficacy, acceptability, and tolerability 3, 5.
• The safety of hydroxyzine has also been evaluated, with results showing that it is associated with a higher rate of sleepiness/drowsiness than active comparators, but is otherwise well-tolerated 3, 5.
• Other studies have investigated the use of benzodiazepines in anxiety disorders, highlighting their widespread use despite concerns about their anxiolytic effectiveness and potential for dependence 6.
• The effects of single-dose anxiolytic medication, including hydroxyzine, on CO2 models of anxiety have also been studied, with results showing no statistically significant differences between hydroxyzine and placebo in terms of subjective anxiolytic effects 7.