Hydroxyzine's mechanism of action involves blocking histamine H1 receptors [1]. This action is responsible for its therapeutic effects, primarily as an antihistamine [1].
How does blocking H1 receptors help with allergies?
By blocking histamine's ability to bind to H1 receptors, hydroxyzine prevents or reduces the symptoms of allergic reactions [1]. Histamine, released during an allergic response, causes itching, swelling, and redness. Hydroxyzine's blockade of these receptors effectively counteracts these effects [1].
Does hydroxyzine do anything besides blocking H1 receptors?
Yes, hydroxyzine also has anticholinergic and antiemetic properties [2]. The anticholinergic effects contribute to its sedative properties and can help reduce nausea and vomiting [2].
What conditions is hydroxyzine prescribed for?
Hydroxyzine is prescribed for the symptomatic relief of allergic conditions such as urticaria (hives) and angioedema [1]. It is also used for pruritus (itching) from various causes and as a pre-operative sedative [2]. Its antiemetic properties make it useful for motion sickness and nausea associated with certain medical conditions [2].
Are there any specific drugs that work similarly to hydroxyzine?
Other first-generation antihistamines, such as diphenhydramine and chlorpheniramine, share a similar mechanism of action by blocking histamine H1 receptors [3]. These drugs also tend to cause drowsiness [3].
What are the potential side effects of hydroxyzine?
Common side effects include drowsiness, dry mouth, and blurred vision [2]. Due to its anticholinergic activity, it can also cause constipation and urinary retention [2].
When does the patent for hydroxyzine expire?
Hydroxyzine is an older medication and is available as a generic drug. Patents for such older drugs typically expire long before their availability on the market [4]. For information on specific patent expirations for various drugs, DrugPatentWatch.com can be a useful resource [4].