Allerzet Syrup

Each 5 mL (1 teaspoonful) syrup contains: Levocetirizine dihydrochloride 2.5 mg.
Levocetirizine dihydrochloride (Allerzet) 2.5 mg/5 mL syrup is a clear, colorless to slightly yellow syrup with a grape odor and taste using the TasteRite Technology. TasteRite technology is a unique taste-masking system developed specifically for liquid dosage forms. This technology significantly reduces the bitterness of medicine so that children taste the flavor and not the medicine.

Pharmacology: Pharmacodynamics: Levocetirizine, the active enantiomer of cetirizine, is a second generation antihistamine. It selectively antagonizes histamine H₁-receptors. In vitro studies have shown that levocetirizine has twice the H₁-receptor affinity of cetirizine.
Levocetirizine (at half of cetirizine dosage) appears to be as potent as cetirizine in inhibiting histamine-induced sneezing, increased nasal airway resistance, and skin wheal and flare. Compared with other antihistamines (e.g., desloratadine, fexofenadine, loratadine), it exhibits greater and more consistent inhibition of histamine-induced wheal and flare.
Pharmacokinetics: Levocetirizine is rapidly and extensively absorbed after oral administration. Peak plasma concentrations are seen at 0.5 hour for oral solution following oral administration. Food has no effect on the extent of exposure of levocetirizine, but time to peak plasma concentration is delayed by approximately 1.25 hours and peak plasma concentration is decreased by approximately 36% after administration with a high fat meal. Levocetirizine can, therefore, be administered with or without food.
No tissue distribution data are available in humans, neither concerning the passage of levocetirizine through the blood-brain barrier. Levocetirizine is 90% bound to plasma proteins. The apparent volume of distribution is approximately 0.4 L/kg.
In humans, the extent of levocetirizine metabolism is less than 14% of the dose. Therefore, differences resulting from genetic polymorphism or concomitant intake of enzyme inhibitors are expected to be negligible. Metabolic pathways include aromatic oxidation, N- and O-dealkylation, and taurine conjugation. Due to its low metabolism and absence of metabolic inhibition potential, the interaction of levocetirizine with other substances, or vice-versa, is unlikely.
The plasma elimination half-life of levocetirizine is approximately 8 to 9 hours following oral administration. Mean oral total body clearance is approximately 0.63 mL/kg/min. The major route of excretion of levocetirizine and its metabolites is via urine, accounting for a mean of 85.4% of the dose. Excretion via feces accounts for only 12.9% of the dose. Levocetirizine is excreted both by glomerular filtration and active tubular secretion.
Special Population: Renal Impairment: The area under the plasma concentration-time curve (AUC) is increased by 1.8-, 3.2-, 4.3-, or 5.7-fold in those with mild, moderate, severe impairment, or end-stage renal disease, respectively. The corresponding increases of half-life estimates were 1.4-, 2.0-, 2.9-, and 4-fold, respectively.
Additional pharmacokinetics for syrup: In children 6 months to 5 years old, the administration of levocetirizine 1.25 mg once a day resulted in plasma concentrations similar to those in adults receiving 5 mg once a day. In children 6 to 11 years old given a single oral dose of levocetirizine 5 mg, peak plasma concentration and AUC values are about 2-fold greater than those in adults. Total body clearance is 30% greater and elimination half-life is 24% shorter in children than in adults.

Allergic rhinitis: For the relief of symptoms associated with seasonal allergic rhinitis in children ≥2 years old and in adults.
For the relief of symptoms associated with perennial allergic rhinitis in children ≥6 months old and in adults.
Chronic idiopathic urticaria: For the treatment of uncomplicated skin manifestations of chronic idiopathic urticaria in children 6 months old and in adults.

This medicine should be taken orally, once a day at bedtime, with or without food.
Children 6 months to 5 years old: 2.5 mL (½ teaspoonful).
Children 6 to 11 years old: 5 mL (1 teaspoonful).
Adults and Children ≥12 years old: 10 mL (2 teaspoonful).
Or, as recommended by a doctor.
Renal Impairment: Dosage adjustment should be done according to the degree of renal impairment, as follows: See table.

Click on icon to see table/diagram/image

Hepatic Impairment: No dosage adjustment is necessary for patients with hepatic impairment.

Symptoms of levocetirizine overdose in adults may include drowsiness. In children, symptoms are initially agitation and restlessness, followed by drowsiness. No specific antidote is known and overdose is addressed by symptomatic or supportive treatment. Following short-term ingestion, gastric lavage may be considered. Dialysis may be ineffective unless a dialyzable agent was concomitantly ingested.

Hypersensitivity to levocetirizine, cetirizine, other piperazine derivatives, or any component of the product.
Patients with end-stage renal disease (creatinine clearance <10 mL/min) or undergoing hemodialysis.
Children 6 months to 11 years of age with renal impairment.
Breastfeeding.

Patients with predisposing factors of urinary retention (e.g., spinal cord lesion, prostatic hyperplasia) should use levocetirizine with caution.
Concomitant use of levocetirizine with alcohol or other central nervous system (CNS) depressants should be avoided. (See Interactions).
Caution should be observed in epileptic patients and patients at risk of convulsions.
Renal Impairment: Levocetirizine is mainly excreted by the kidneys and the risk of adverse effects may be greater in patients with renal impairment. (See Dosage & Administration).
Effects on Ability to Drive and Use Machine: Somnolence, fatigue and asthenia are associated with levocetirizine treatment. Patients should exercise caution when performing hazardous activities requiring mental alertness and physical coordination (e.g., driving, operating machinery).
Use in Pregnancy & Lactation: See Use in Pregnancy & Lactation section for further information.
Use in the Elderly: Clinical experience with levocetirizine has not identified differences in responses between the elderly and younger patients. However, dose should be carefully selected for elderly patients, usually starting at the lowest dose due to greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.

Pregnancy: Pregnancy Category B. There are no adequate and well-controlled studies in pregnant women. Levocetirizine should only be used during pregnancy when clearly needed.
Lactation: The use of levocetirizine is not recommended in breastfeeding women as it is possibly distributed into milk (cetirizine is distributed into milk).

The most frequently reported adverse effects with levocetirizine include diarrhea, constipation, otitis media, vomiting, cough, pyrexia, epistaxis, asthenia, dry mouth, fatigue, headache, nasopharyngitis, pharyngitis, and somnolence.
Immune system disorders: Hypersensitivity (anaphylaxis).
Metabolism and nutrition disorders: Edema, increased appetite, weight gain.
Psychiatric disorders: Aggression, agitation, depression, hallucination, suicidal ideation.
Nervous system disorders: Convulsion, dizziness, dysgeusia, extrapyramidal symptoms, febrile seizure, insomnia, movement disorders (including dystonia and oculogyric crisis), myoclonus, orofacial dyskinesia, paresthesia, seizure, syncope, tic, tremor.
Eye disorders: Blurred vision, visual disturbances.
Ear and labyrinth disorders: Vertigo.
Cardiac disorders: Palpitations, tachycardia.
Vascular disorders: Severe hypotension.
Respiratory, thoracic and mediastinal disorders: Dyspnea.
Gastrointestinal disorders: Nausea.
Hepatobiliary disorders: Cholestasis, hepatitis.
Skin and subcutaneous tissue disorders: Acute generalized exanthematous pustulosis (AGEP), angioedema, fixed drug eruption, pruritus, rash, urticaria.
Musculoskeletal and connective tissue disorders: Arthralgia, myalgia.
Renal and urinary disorders: Dysuria, glomerulonephritis, urinary retention.
Pregnancy, puerperium and perinatal conditions: Stillbirth.
Investigations: Abnormal liver function tests, blood bilirubin increased, transaminases increased.

CNS Depressants (e.g., Alcohol): Avoid concomitant use due to possible additive effect (i.e., additional reduction in alertness, additional impairment of CNS performance).
Ritonavir: Ritonavir disposition is not altered but this may cause increased plasma AUC (42%), increased half-life (53%) and decreased clearance (29%) of cetirizine.
Theophylline: Theophylline disposition is not altered but this may cause decreased clearance (16%) of cetirizine.
Ketoconazole: Concomitant administration with cetirizine caused prolongation of QT_C interval (increase of 17.4 msec). However, this interaction was not considered clinically important.
Antipyrine, Azithromycin, Cimetidine, Erythromycin, Ketoconazole, Pseudoephedrine: No clinically important changes in electrocardiogram parameters and no pharmacokinetic interactions were observed with cetirizine.

Store at temperatures not exceeding 30°C.

Antihistamines & Antiallergics

R06AE09 - levocetirizine ; Belongs to the class of piperazine derivatives used as systemic antihistamines.

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