Anxiolytics hydroxyzine

Antihistamines. Some clinicians have prescribed the antihistamine, hydroxyzine (Vistaril, Atarax) to treat anxiety. A typical regimen is 25 mg administered one to three times per day as needed for anxiety. The use of hydroxyzine to treat anxiety is largely driven by concern regarding the addictive potential of benzodiazepines. In reality, hydroxyzine does little to relieve anxiety other than produce drowsiness. Because other nonaddictive anxiolytics are available, we do not recommend routine use of this largely ineffective treatment. 

The longstanding use in some countries of hydroxyzine, a centrally-acting Hi-histamine receptor antagonist, is supported by positive findings in controlled trials in GAD (Ferreri and Hantouche 1998 Lader and Scotto 1998). Hydroxyzine promotes sleep and its anxiolytic effects have an early onset. Although it causes sedation, tolerance to this effect often occurs and effects on psychomotor performance are smaller than with benzodiazepines (de Brabander and Deberdt 1990). It is well-tolerated and withdrawal effects have not been reported. Although the evidence for its efficacy is not large, hydroxyzine provides an option for some patients with GAD for whom standard treatments are unsuitable. 

Several Hi histamine antagonists (e.g., diphenhydramine, promethazine, and hydroxyzine) have been used as sedative-hypnotics, since they produce some degree of sedation. While this sedation is usually considered a side effect of their antihistaminic activity, in some cases the sedation is sufficient to allow the drugs to be used in the treatment of anxiety and sleep disturbances. For these drugs, the anxiolytic properties are thought to be a direct consequence of their ability to produce sedation. 

The first generation Hi blockers (including diphenhydramine and hydroxyzine) cross the blood-brain barrier. Subsequent generations of antihistamines have been developed so that they do not cross the blood-brain barrier, and therefore are not effective as sedatives or anxiolytics. 

Numerous clinical trials have also attested to the anxiolytic efficacy of hydroxyzine. Controlled trials have confirmed its efficacy and safety at a fixed dose of 50 mg in GAD (64). In a double-blind, parallel-group, multicenter study in France and Great Britain, a total of 244 patients with GAD were allocated randomly to treatment with hydroxyzine (12.5 mg t.i.d.), buspirone 5 mg morning and midday and 10 mg in the evening, or placebo. The results showed both hydroxyzine and buspirone to be more efficacious than placebo, indicating that hydroxyzine can be a useful treatment for GAD (65). 

Other than slow taper, no consistently effective treatment to alleviate withdrawal symptoms has been reported. Although several compounds have been studied (e.g., b-blockers, clonidine, carbamazepine, abercamil, ondansetron), results have been contradictory ( 250). Carbamazepine, however, may be useful in seizure-prone patients (251). Valproate (VPA) has also been reported to benefit patients undergoing BZD discontinuation after long-term dependence ( 252), which may be related to VPA s potential anxiolytic properties, its ability to alleviate withdrawal phenomena, or both. The azaspirone anxiolytic buspirone has been reported ineffective in suppressing withdrawal symptoms, particularly in long-term BZD users (253, 254). Hydroxyzine has also been found beneficial in treating patients for lorazepam withdrawal (255). 

Corned answer = B. The anxiolytic properties of benzodiazepines, such as lorazepam, make them the drugs of choice in treating the anxiety and agitation of cocaine withdrawal. Lorazepam also has hypnotic properties. Phenobaibital has hypnotic properties but if s anxiolytic properties are inferior to those of the benzodiazepines. Cocaine itself could countered the agitation of withdrawal but its use would not be proper therapy. Hydroxyzine, an antihistaminic, is effective as an hypnotic and is sometimes used to deal with anxiety especially if emesis is a problem. Fluoxetine is an antidepressant with no immediate effects on anxiety. 

Lader M. Anxiolytic effect of hydroxyzine a double-blind trial versus placebo buspirone. Hum Psychopharmacol 1999 14(Suppl 1) 94-102. 

Hydroxyzine was effective in 88% of patients for a duration of 3 months. Pregabalin produced anxiolytic effects similar to lorazepam, alprazolam, and venlafaxine in acute trials. Sedation and dizziness were the most common adverse effects, and the dose should be tapered over 1 week upon discontinuation. 

Antihistamines (Hj receptor), especially chlor-phenamine and hydroxyzine orally, are used for their sedative or anxiolytic effect (except in urticaria) they should not be appHed topically over a prolonged period for risk of allergy. 

ANTAGONIST activity. It is a sedative/tranquillizer with ANXIOLYTIC activity, and can be used in preoperative medication, as an antiemetic and for the relief of itching. Hydroxyzine trimethoxybenzoate has been used as an ANTI ARRHYTHMIC. 

A visible effect of the solubility modifications happening after introduction of a carboxylic group is found in the history of antihistaminic compounds (Figure 20.49). The first generation of antihistaminic drugs, in which hydroxyzine, were lipophilic compounds. They were able to cross the BBB, and had a sedating action because they were not P-glycoprotein (P-gp) substrate (which means they were not considered as xenobiotics and pumped out of the brain). Nowadays, hydroxyzine is still used as anxiolytic. 

Tlydroxyzine and kava kava are two alternatives. Patients with GAD demonstrated contmned efficacy for 3 months with hydroxyzine or bromazepam (not marketed in the United States), but not with placebo. Efficacy was maintained in 86% of the hydroxyzine group and 88% of the bromazepam group. A meta-analysis of randomized trials comparing the herbal preparation kava kava found it was more effective than placebo for anxiety during trial durations of 1 to 24 weeks. Many patients experienced CNS effects (e.g., tremors, drowsiness, restlessness, and headaches) and abdominal discomfort during short-term treatment. Because of recent reports of hepato-toxicity, kava kava is not recommended as an anxiolytic. ... 

Some of this classification is not pure in that agents in some subcategories have multiple pharmacological properties that are frequently of clinical usefulness and not necessarily related to psychotropic effects. For example, some of the minor tranquilizers include members that have excellent skeletal muscle relaxant properties several are used as antiepileptics (e.g., diazepam). The diphenylmethane derivative hydroxyzine is a particularly good example of multiple pharmacology. In addition to its anxiolytic (antianxiety) property, it also exhibits the following clinically significant assets antihistaminic, adrenolytic, antiemetic, antispasmodic, hypothermic, and sedative effects. 

AI3-50162 Alamon Atarax Atarax dihydrochloride Ataraxoid dihydroohloride Aterax Aterax dihydro-chloride Durrax EINECS 218-586-3 Hydroxyzine dihydroohloride Hydroxyzine hydrochloride Marax Neurolax Orgatrax Quiess QYS Tran-Q dihydro-chloride Tranquizine dihydroohloride Vistaril Parenteral Vistaril steraject. A Hi receptor antagonist. Anxiolytic antihistaminic. Has been used as a minor tranquillizer. Crystals mp = 193° soluble in H2O (<70 g/100 ml), CHCI3 (6 g/100 ml), MezCO (0.2 g/100 ml), EtzO (< 0,01 g/100... 

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