Benadryl One

Cetirizine hydrochloride (Benadryl One) is a piperazine derivative and a metabolite of hydroxyzine. It competes reversibly with histamine to block the histamine (H1) receptor sites. Cetirizine hydrochloride is considered a long-acting non-sedating antihistamine and has some mast-cell stabilizing activity.
Cetirizine hydrochloride (Benadryl One) is a long-acting anti-histamine causing little or no drowsiness. It does not demonstrate any antimuscarinic activity. This drug competes reversibly with histamines which are released from mast cells. Once bound to H1 receptor sites in the tissues, cetirizine hydrochloride inhibits histamine-induced allergic reactions by blocking eosinophil infiltration to the site of allergen-induced cutaneous reactions.

Antihistamine (Piperazine Derivative).

Cetirizine hydrochloride (Benadryl One) is used for the symptomatic relief of allergic conditions including rhinitis and chronic urticaria.

Adult and Children 6 years and older: Given orally at 10 mg per day. There was no additional benefit seen in increasing dose of Cetirizine HCl (Benadryl One) to 20 mg.
Or as prescribed by the physician.
Hepatic Impairment (patients with liver problems or diseases): The dose should be reduced to half their usual dose per day.
Renal Impairment (patients with kidney problems or diseases): The dose should be reduced to half their usual dose per day.
Seasonal Rhinitis: It is recommended that Cetirizine hydrochloride (Benadryl One) be given at the beginning of hay fever season when pollens are still few.
Cetirizine hydrochloride (Benadryl One) may be administered with or without food as it will not affect absorption of the drug.
What should the patient do if they miss a dose: Continue medication based on dosage and/or consult the doctor.

Signs and symptoms of overdose: Overdose of Cetirizine hydrochloride (Benadryl One) (180 mg) caused restlessness, irritability and drowsiness in an 18-month old child. In adults, drowsiness, upon ingestion of 150 mg Cetirizine hydrochloride (Benadryl One) has been reported.
A case of a hypokalemic dialyzed patient with chronic renal failure, was reported to develop symptomatic episodes of torsades de pointes after overdosage with Cetirizine hydrochloride (Benadryl One).
What to do when the patient has taken more than the recommended dosage: Consult the doctor if patient has taken more than the recommended dosage.

Cetirizine hydrochloride (Benadryl One) is contraindicated to those who are allergic to cetirizine, hydroxyzine, or any component of the formulation.
Cetirizine hydrochloride (Benadryl One) is not recommended to be given to hypokalemic patients with chronic renal failure undergoing hemodialysis. (See Overdosage.)
It should not be given to children with hepatic and renal impairment, who are younger than 6 years of age.

Cetirizine hydrochloride (Benadryl One) should be used with caution in patients who require mental alertness or physical coordination in their work such as drivers or machine operators since it may cause drowsiness.
Use in Pregnancy & Lactation: See USE IN PREGNANCY & LACTATION section for further information.
Use in Children: Use in Infants: Infants and children must not be given cetirizine hydrochloride as this may increase the risk of experiencing antimuscarinic effects.
Use in the Elderly: Cetirizine hydrochloride (Benadryl One) must be used with caution in elderly patients who most likely have impaired renal and hepatic function. Since the drug is metabolized through the renal mechanism, half-life of Cetirizine hydrochloride (Benadryl One) in such patients will be prolonged. Dose of the drug must be reduced in elderly patients.

Use in Pregnant Women: No data is available on the safety of administration of cetirizine hydrochloride (Benadryl One) in pregnant women apart from an animal study which reveals absence of teratogenicity. As such, cetirizine hydrochloride must be given to pregnant patients only when necessary.
Use in Lactating Mothers: Cetirizine hydrochloride (Benadryl One) is excreted in breast milk. Thus, use in lactating mothers is not recommended.

Cetirizine hydrochloride (Benadryl One), though considered as a "non-sedating" antihistamine, was found to cause drowsiness in some people.
Recurrent acute hepatitis developed in one patient taking Cetirizine hydrochloride (Benadryl One) for control of seasonal allergic rhinitis.
Other adverse effects associated with the use of Cetirizine hydrochloride are irritability, insomnia, somnolence, fatigue, dry mouth, pharyngitis, dizziness, headache, abdominal pain, cough, diarrhea, epistaxis, bronchospasm, nausea and vomiting and hypersensitivity manifested by urticarial and fixed drug eruptions.
Although Cetirizine hydrochloride has low potential for hepatotoxicity, the possibility of developing autoimmune-mediated hepatotoxicity should be considered when administering the drug. A patient under long-term treatment with Cetirizine hydrochloride (Benadryl One) for atopic dermatitis was reported to have developed life-threatening hepatitis.

Sedation may be enhanced upon concomitant use of antihistamines in general with central nervous system depressants such as barbiturates, alcohol, hypnotics, opioid analgesics, anxiolytic sedatives and neuroleptics.
The use of Cetirizine hydrochloride (Benadryl One) with drugs that inhibit the cytochrome P-450 microsomal enzymes such as azithromycin, erythromycin and ketoconazole, did not cause clinically significant changes.
Effects of alcohol and other Central Nervous System (CNS) depressants are enhanced by Cetirizine hydrochloride (Benadryl One).
Pharmacokinetic properties of ritonavir, HIV protease inhibitor, are not affected by Cetirizine hydrochloride (Benadryl One).

Store at temperatures not exceeding 30°C.

Antihistamines & Antiallergics

R06AE07 - cetirizine ; Belongs to the class of piperazine derivatives used as systemic antihistamines.

Non-Rx