Atarax

Atarax (hydroxyzine) works by blocking the activity of histamine, which is the substance that triggers the symptoms of allergies. It also exerts its action as a sedative on the central nervous system and can act as an antiemetic, acting as an antagonist of the neurotransmitter acetylcholine.

Atarax is used to relieve the itching triggered by allergic phenomena (such as, for example, chronic urticaria, dermatitis, reactions associated with histamine) as well as to control nausea and vomiting of different origins, including car sickness. It also finds use as an anxiolytic and for treating alcohol withdrawal symptoms.

Histamine is a mediator that exercises its physiological action by binding to receptors of 3 types: H1, H2 and H3. These receptors mediate inflammatory responses (H1), gastric secretion (H2) and central activity (H3). Histamine mediates pain stimuli in nerve endings, induces bronchoconstriction, skin redness and hypotension. It is also contained in mast cells and basophilic granulocytes and is released during the inflammatory process following the link between the antibody (immunoglobulin E) and the mast cell membrane; there is the release of histamine, which is contained in granules (this release is therefore called degranulation, and involves vasoconstriction, edema and activation of mediators typical of inflammation). Atarax is a selective antagonist for H1 receptors as an antiallergic agent, able to act as competitive inhibitors on the H1 receptor.

As for its anxiolytic action, the effects of hydroxyzine are produced rapidly; Atarax does not generate dependence and memory impairment, unlike benzodiazepine. The secondary effect of Atarax, which is considered more important, is the sedating one, but this tends to decrease with time. Hydroxyzine fights anxiety basically by acting as a histamine receptor blocker.

Atarax is used orally, rapidly absorbed, extensively metabolized in the liver by the CyP450 enzyme complex. The metabolites are still active. The duration of action generally is around 4-6 hours.

For Atarax therapy to be safe, the following drugs interactions should be observed. Important interactions have been reported with some antibiotics such as ketoconazole and itraconazole (azole drugs) or macrolides that inhibit CyP450, increasing the plasma concentration of antihistamines up to the most important toxic effects. Other interactions may occur with sedative drugs, whose sedation may increase due to effect synergy.

Atarax is usually taken by mouth in the form of capsules, tablets, syrups or suspensions to be taken 3-4 times a day. The maximum dose in adults should not exceed 100 mg per day, while it is 50 mg for the elderly. For children up to 40 kilos the maximum dose is 2 mg per kilo per day, while for those over 40 kilos the adult dose can be administered.

Among its potential side effects the following are included:

• dry mouth
• dry nasal mucosa
• dry throat
• stomach problems
• sense of drowsiness
• dizziness
• chest congestion
• headache
• skin redness

It is recommended to contact a doctor immediately in the case of:

• difficulty breathing
• weakness in the muscles
• state of anxiety on the rise

Before taking it, the doctor should be informed:

• about the presence of active ingredient allergies, its excipients or any other drug
• of medicines, herbal medicines and supplements already taken in the past (remembering in particular to mention antihistamines, sedatives, sleeping drugs, tranquilizers, medicines against colds, allergies or hay fever, antidepressants, muscle relaxants, narcotics, anticonvulsants and vitamin A)
• if you suffer (or have suffered in the past) from asthma, high blood pressure, convulsions, glaucoma, ulcers, urination difficulties caused by prostatic hypertrophy, heart or liver disease or hyperthyroidism
• in the case of pregnant or lactating women

It is always advised to inform doctors, surgeons and dentists of an ongoing hydroxyzine treatment.

This medicine can compromise the ability to drive or maneuver dangerous machinery and alcohol can increase the side effects.

The drug is contraindicated in subjects with known hypersensitivity to the active ingredient or to any of the excipients, to cetirizine, to other piperazine derivatives, to aminophylline or to ethylenediamine. Additional contraindications are the treatment with monoamine oxidase inhibitors (MAOIs) and the pre-existence of a prolonged QT interval. Unless otherwise indicated, the drug should not be given to children under the age of 12. Finally, the molecule is contraindicated in pregnant women and breast-feeding women.

The nonproprietary (generic) name of Atarax is hydroxyzine, which is the name of the active substance used as its basis and the main medicinal component of the drug.