We regularly hear about the uses and benefits of hydroxyzine . Here we tell you all the details about this antihistamine.
Hydroxyzine – What is it
Hydroxyzine, sold under the brand names Atarax and Vistaril among others, is a first-generation antihistamine. It was first synthesized by Union Chimique Belge in 1956 and was marketed by Pfizer in the United States later that year and is still widely used today.
Hydroxyzine – Uses
Due to its antihistamine effects, it can be used to treat severe cases of itching, hyperalgesia, and nausea induced by dizziness; It has also been used in some cases to alleviate the effects of opiate withdrawal. Although it is an effective sedative, hypnotic, and anxiolytic, it shares virtually none of the abuse, dependence, addiction, and toxicity potential of other drugs used for the same range of therapeutic reasons. Hydroxyzine has also been used to enhance opioid analgesia and alleviate some of its side effects, such as itching, nausea, and vomiting.
Due to its antagonistic effects on various receptor systems in the brain, hydroxyzine also has anxiolytic, antiobsessive, and antipsychotic activity.
Hydroxyzine is classified as an antihistamine and anxiolytic and is also used as a tranquilizer, especially in dentistry and less so in medicine, where for many years it has been preferred in combination with opioids due to its ability to counteract the side effects of opioid pain. medications, that is, itching and nausea, and the fact that their sedative properties complement the analgesic effects of opioids.
Hydroxyzine is prescribed when the onset of an organic disease state manifests itself through anxiety, such as a generalized anxiety disorder, or in other more serious cases such as psychoneurosis, and is therefore prescribed as a means of regulating the normal function.
For dentistry and obstetrics, as well as other surgeries and procedures and situations of acute pain such as accidents, hydroxyzine is useful as a first-line anxiolytic and opiate adjuvant because it lacks antagonism and synergy with benzodiazepines and scopolamine, which allows the use of any of these agents simultaneously or later in the procedure if necessary.
Hydroxyzine – Contraindications
Administration of hydroxyzine in large amounts by ingestion or intramuscular administration during early pregnancy can cause fetal abnormalities: when administered to pregnant rats, mice, and rabbits, hydroxyzine causes abnormalities such as hypogonadism at doses significantly above the human therapeutic range . In humans, a significant dose has not yet been established in studies and, by default, the FDA has introduced contraindication guidelines regarding hydroxyzine.
There have also been studies showing that long-term hydroxyzine prescription can lead to tardive dyskinesia after years of use, but dyskinesia-related effects were also anecdotally reported after 7.5-month periods, such as continuously rolling the head, lip licking and other forms of athetoid movement. In certain cases, previous interactions of the elderly patients with phenothiazine derivatives or pre-existing neuroleptic treatment may have had some contribution to dyskinesia in the administration of hydroxyzine due to hypersensitivity caused by prolonged treatment, and therefore, Some contraindications are given long-term administration of hydroxyzine to those with previous use of phenothiazine.
Hydroxyzine – Side Effects
Several reactions have been observed in the manufacturer’s guidelines: cases of deep sleep, incoordination, sedation, calm and dizziness have been reported in children and adults, as well as others such as hypotension, tinnitus and headaches. Gastrointestinal effects have also been observed, as well as less serious effects such as dry mouth and constipation caused by the mild antimuscarinic properties of hydroxyzine.
In rare cases, central nervous system problems, such as hallucinations or confusion, have been observed, mainly attributed to overdose. Such properties have been attributed to hydroxyzine in several cases, particularly in patients treated for neuropsychological disorders, as well as in cases where overdoses have been observed. While there are reports of hydroxyzine’s “hallucinogenic” or “hypnotic” properties, several clinical data trials did not report these side effects from hydroxyzine consumption alone, but instead described its overall calming effect described through stimulation of areas the formatio reticularis. The hallucinogenic or hypnotic properties have been described as an additional effect of the general suppression of the central nervous system by other CNS agents,
The effect of hydroxyzine has also been tested on the ability of humans to record and store memory, and was used in comparison with relatively safe drugs, such as lorazepam, to illustrate the effects of benzodiazepines, which are believed to have effects adverse memory storage capacity. Hydroxyzine was found to have no adverse effects on memory relative to lorazepam, causing several deficiencies in memory storage capacity.
Hydroxyzine – Pharmacology
The predominant mechanism of action of hydroxyzine is as a potent and selective agonist of the histamine H1 receptor. This action is responsible for its antihistamine and sedative effects. Unlike many other first-generation antihistamines, hydroxyzine has a very low affinity for muscarinic acetylcholine receptors and accordingly has little or no propensity for anticholinergic side effects.
Dr. Samantha Robson ( CRN: 0510146-5) is a nutritionist and website content reviewer related to her area of expertise. With a postgraduate degree in Nutrition from The University of Arizona, she is a specialist in Sports Nutrition from Oxford University and is also a member of the International Society of Sports Nutrition.