Histan

Hydroxyzine hydrochloride.

Film-coated tablet: White, round and biconvex film-coated tablet with plain on one side and logo "
Click on icon to see table/diagram/image
" on the other side.
Each tablet contains Hydroxyzine hydrochloride 10 mg.
Oral solution: Clear pink solution with strawberry odor.
Each 5 mL contains Hydroxyzine hydrochloride 10 mg.
Syrup: Each 5 mL contains Hydroxyzine hydrochloride 10 mg.

Pharmacology: Pharmacodynamics: Hydroxyzine is a piperazine-derivative antihistamine. It is a first-generation antihistamine which binds nonselectively to central and peripheral H₁ receptors. Hydroxyzine is a sedating antihistamine with antimuscarinic and significant sedative properties. Its main use is as an anxiolytic. It is also used as an adjunct to premedication and in the management of pruritus and urticaria.
Hydroxyzine appears to be the most potent antihistamine in alleviating IgE-mediated pruritus and urticaria.
Hydroxyzine suppresses the wheal-and-flare response in the skin for greater than 24 hours.
The sedative and tranquilizing effects of Hydroxyzine are thought to result principally from suppression of activity at subcortical levels of the CNS; the drug does not have cortical depressant activity.
Pharmacokinetics: Absorption: Hydroxyzine is rapidly absorbed from the gastrointestinal tract. The peak plasma level (C_max) is reached approximately 2 hours after oral intake. The sedative effects begin approximately 15-30 minutes after oral intake and the sedative effect lasts for 4-6 hours.
Distribution: Hydroxyzine is widely distributed into most body tissues and fluids with highest generally concentration in the liver, lung, spleen, kidney and adipose tissue. The apparent volume of distribution is 16 L/kg in adults.
Metabolism: Hydroxyzine is metabolized in the liver by alcohol dehydrogenase and cytochrome P450 isoenzymes CYP3A4 and CYP3A5. The major metabolite of Hydroxyzine is cetirizine, which is a carboxylic acid metabolite. This metabolite has significant peripheral H₁-antagonist properties and long-acting antihistamine.
Elimination: Hydroxyzine and antihistamine metabolites (including small amounts of unchanged drug) are excreted in the urine. An elimination half-life of about 20 and 25 hours have been reported for Hydroxyzine and cetirizine, respectively.

Use for relieving pruritus due to allergic conditions e.g., urticaria, contact dermatitis or histamine-mediated pruritus.
As a sedative when used as premedication and following general anesthesia.
Symptomatic relief of anxiety.

The medication should be taken as directed or as directed by physician.
Pruritus: Adults: 25 mg orally, 3 to 4 times daily.
Children (more than 6 years): Initial as 15-25 mg per day, if necessary, the oral dose may be increased to 50 to 100 mg per day in divided doses.
Children (6 months to 6 years): Initial as 5-15 mg per day, if necessary, the oral dose may be increased to 50 mg per day in divided doses.
Sedation: For using as premedication and following general anesthesia: Adults: 50-100 mg orally per dose.
Children: 0.6 mg per kg orally.
Anxiety: Adults: Film-coated tablet/Syrup: 25-100 mg, 4 times daily. Maximum dose: 600 mg daily.
Oral solution: 50-100 mg orally, 4 times daily.
Children (more than 6 years): 50 to 100 mg per day orally in divided doses.
Children (younger than 6 years): 50 mg per day orally in divided doses.
The use of Hydroxyzine in the treatment of anxiety and stress should be periodically evaluated for its efficacy.
Dosage in hepatic insufficiency or renal impairment: Patients with hepatic insufficiency: The dose of Hydroxyzine should be reduced to 1/3 of the total daily dose.
Patients with moderate to severe renal impairment: The dose of Hydroxyzine should be reduced to half.

Overdose and treatment: Anticholinergic (primarily antimuscarinic) effects develop in overdose. Mild to moderate poisoning effects for example somnolence, anticholinergic effects (i.e., mydriasis, flushing, fever, dry mouth, and decreased bowel sounds), tachycardia, mild hypertension, and nausea and vomiting are common after overdose. Agitation, confusion, and hallucinations may develop with moderate poisoning. Severe poisoning effects may include agitated delirium, psychosis, seizures, coma, hypotension, QRS widening, and ventricular dysrhythmias, including torsade de pointes but are generally only reported in adults after very large, deliberate ingestions.
In the event of an overdose, supportive management is recommended. However, hemodialysis or peritoneal dialysis is probably not effective in enhancing elimination of Hydroxyzine. There is no specific antidote for Hydroxyzine intoxication. Activated charcoal should be given if patient presents shortly after ingestion; sedate with benzodiazepines for agitation and delirium. If hypotension occurs, it may be controlled with IV fluids and norepinephrine or metaraminol; epinephrine should not be used. Further management, such as patients with severe toxicity (i.e., seizures, dysrhythmias, severe delirium, coma) or in whom the diagnosis is not clear, should be as clinically indicated or as recommended by the poison center, where available. A patient with a deliberate overdose requires a psychiatric evaluation prior to discharge.

Hydroxyzine hydrochloride is contraindicated in: Patients with a history of hypersensitivity to Hydroxyzine hydrochloride, cetirizine, levocetirizine or any of the piperazine derivatives or formulation components.
Use in Pregnancy & Lactation: Women who are pregnant during the first 3 months and women who are breastfeeding.
Film-coated tablet/Syrup: Premature infants.
Oral solution: Patients with QT interval prolongation or who have risk factors.

(Based on the Ministry of Public Health's Announcement): Hydroxyzine hydrochloride is contraindicated in patients with risk factor for cardiac arrhythmias or in combination with other drugs that increase risk of abnormal electrocardiogram e.g. erythromycin.
This medicine should not be used in the elderly and the dose should not exceed 100 mg/day for adults, 50 mg/day for the elderly, or 2 mg/kg/day for children weighing less than 40 kg.
Use the lowest dosage necessary to achieve a therapeutic effect and use for the shortest duration.
This medicine may cause drowsiness therefore should not drive or operate machinery or perform activities which may be at risk of falling from the height.
While using this medicine, should not drink alcohol or anything that is mixed with alcohol.
This medicine can cause dry mouth, dysuria, thick mucus, blurred vision, dizziness and confusion.
Use with caution in combination with CNS suppressants e.g., benzodiazines, anticholinergic drugs and antidepressant drugs.
Use with caution in patients with high blood pressure, cardiovascular disease, hyperthyroid, patients with a history of asthma, or emphysema.
Use in Pregnancy & Lactation: This medicine should not be used in the first trimester pregnancy and breast-feeding.
Use in Children and the Elderly: Children and the elderly are more sensitive to this drug, causing drowsiness, dizziness, hallucinations, dry mouth, urinary retention, low blood pressure, irritability, insomnia and, in some cases, seizures (Paradoxical reaction).

QT prolongation/torsades de pointes has been reported with the majority occurring in patients with other risk factors for QT prolongation/torsades de pointes (e.g., preexisting cardiac disease, electrolyte imbalances, concomitant arrhythmogenic use). Use with caution in patients with risk factors for QT prolongation, congenital long QT syndrome, a family history of long QT syndrome, other conditions that predispose to QT prolongation and ventricular arrhythmia, as well as recent myocardial infarction, uncompensated heart failure, and bradyarrhythmias.
Use with caution with narrow-angle glaucoma, prostatic hyperplasia, urinary stricture, asthma, or COPD.
Effect on ability to drive and use machine: Hydroxyzine may cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (e.g., operating machinery or driving).

Pregnancy: Although there are no adequate and controlled studies to date in humans, Hydroxyzine has been shown to be teratogenic in mice, rats, and rabbits when given at dosages substantially greater than the therapeutic human dosage. Pending accumulation of further data regarding safety in pregnant women, Hydroxyzine is contraindicated during early pregnancy.
Breast-feeding: It is unknown whether Hydroxyzine is excreted in human milk. Hydroxyzine should not be used in women who are breastfeeding.

Nervous system disorders: Drowsiness, dizziness, ataxia, weakness, slurred speech, headache, agitation, increased anxiety, tremor, seizure.
Gastrointestinal disorders: Dry mouth, nausea, taste bitter, increased GI peristalsis.
Respiratory disorders: Wheezing, tightness of the chest.
Skin and subcutaneous tissue disorders: Flushing, acute generalized exanthematous pustulosis (AGEP), fixed drug eruption, skin rash.
Cardiovascular disorders: QT interval prolongation, torsade de pointes, hypotension.
Film-coated tablet/Syrup: Lassitude, urinary retention.

Hydroxyzine may be additive with, or may potentiate the action of other CNS depressants (e.g. opiates or other analgesics, barbiturates or other sedatives, anesthetics, or alcohol). When Hydroxyzine is used concomitantly with other CNS depressants, caution should be used to avoid excessive sedation, and recommend that dosage of the CNS depressant can be reduced by up to 50%. Hydroxyzine has been shown to inhibit and reverse the vasopressor effect of epinephrine. If a vasopressor agent is required in patients receiving Hydroxyzine, norepinephrine or metaraminol should be used but epinephrine should not be used. Potent inhibitors of alcohol dehydrogenase or CYP3A4/5 may increase blood concentrations of Hydroxyzine. Hydroxyzine is an inhibitor of CYP2D6 which may lead to additive effects with some substrates of this isoenzyme.
Concomitant administration of Hydroxyzine with drugs known to prolong the QT interval and/or induce torsade de pointes such as class III antiarrhythmics (e.g. amiodarone, sotalol), some antidepressants (e.g. citalopram), some antibiotics (e.g. sparfloxacin), methadone etc., should be avoided. Additive anticholinergic effects may also occur when Hydroxyzine is administered concomitantly with other anticholinergic agents.

Store below 30°C, protect from light.

Antihistamines & Antiallergics / Anxiolytics

N05BB01 - hydroxyzine ; Belongs to the class of diphenylmethane derivatives anxiolytics. Used in the management of anxiety, agitation or tension.

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