Adults and Children 12 Years of Age and Older

The recommended dose of levocetirizine dihydrochloride tablets is 5 mg (1 tablet) once daily in the evening. Some patients may be adequately controlled by 2.5 mg (1/2 tablet) once daily in the evening.

Children 6 to 11 Years of Age

The recommended dose of levocetirizine dihydrochloride tablets is 2.5 mg (1/2 tablet) once daily in the evening. The 2.5 mg dose should not be exceeded because the systemic exposure with 5 mg is approximately twice that of adults [see Clinical Pharmacology (12.3)].

Dose Adjustment for Renal and Hepatic Impairment

In adults and children 12 years of age and older with:

• Mild renal impairment (creatinine clearance [CLCR] = 50 to 80 mL/min): a dose of 2.5 mg once daily is recommended;
• Moderate renal impairment (CLCR = 30 to 50 mL/min): a dose of 2.5 mg once every other day is recommended;
• Severe renal impairment (CLCR = 10 to 30 mL/min): a dose of 2.5 mg twice weekly (administered once every 3 to 4 days) is recommended;
• End-stage renal disease patients (CLCR < 10 mL/min) and patients undergoing hemodialysis should not receive levocetirizine dihydrochloride.

No dose adjustment is needed in patients with solely hepatic impairment. In patients with both hepatic impairment and renal impairment, adjustment of the dose is recommended.

Adults and Adolescents 12 years of Age and Older

In studies up to 6 weeks in duration, the mean age of the adult and adolescent patients was 32 years, 44% of the patients were men and 56% were women, and the large majority (more than 90%) was Caucasian.

In these trials 43% and 42% of the subjects in the levocetirizine dihydrochloride 2.5 mg and 5 mg groups, respectively, had at least one adverse event compared to 43% in the placebo group.

In placebo-controlled trials of 1 to 6 weeks in duration, the most common adverse reactions were somnolence, nasopharyngitis, fatigue, dry mouth, and pharyngitis, and most were mild to moderate in intensity. Somnolence with levocetirizine dihydrochloride showed dose ordering between tested doses of 2.5 mg, 5 mg and 10 mg and was the most common adverse reaction leading to discontinuation (0.5%).

Table 1 lists adverse reactions that were reported in greater than or equal to 2% of subjects aged 12 years and older exposed to levocetirizine dihydrochloride 2.5 mg or 5 mg in eight placebo-controlled clinical trials and that were more common with levocetirizine dihydrochloride than placebo.

Additional adverse reactions of medical significance observed at a higher incidence than in placebo in adults and adolescents aged 12 years and older exposed to levocetirizine dihydrochloride are syncope (0.2%) and weight increased (0.5%).

Pediatric Patients 6 to 12 Years of Age

A total of 243 pediatric patients 6 to 12 years of age received levocetirizine dihydrochloride 5 mg once daily in two short-term placebo controlled double-blind trials. The mean age of the patients was 9.8 years, 79 (32%) were 6 to 8 years of age, and 50% were Caucasian. Table 2 lists adverse reactions that were reported in greater than or equal to 2% of subjects aged 6 to 12 years exposed to levocetirizine dihydrochloride 5 mg in placebo-controlled clinical trials and that were more common with levocetirizine dihydrochloride than placebo.

Pediatric Patients 1 to 5 Years of Age

A total of 114 pediatric patients 1 to 5 years of age received levocetirizine dihydrochloride 1.25 mg twice daily in a two week placebo-controlled double-blind safety trial. The mean age of the patients was 3.8 years, 32% were 1 to 2 years of age, 71% were Caucasian and 18% were Black. Table 3 lists adverse reactions that were reported in greater than or equal to 2% of subjects aged 1 to 5 years exposed to levocetirizine dihydrochloride 1.25 mg twice daily in the placebo-controlled safety trial and that were more common with levocetirizine dihydrochloride than placebo.

Pediatric Patients 6 to 11 Months of Age

A total of 45 pediatric patients 6 to 11 months of age received levocetirizine dihydrochloride 1.25 mg once daily in a two week placebo-controlled double-blind safety trial. The mean age of the patients was 9 months, 51% were Caucasian and 31% were Black. Adverse reactions that were reported in more than 1 subject (i.e. greater than or equal to 3% of subjects) aged 6 to 11 months exposed to levocetirizine dihydrochloride 1.25 mg once daily in the placebo-controlled safety trial and that were more common with levocetirizine dihydrochloride than placebo included diarrhea and constipation which were reported in 6 (13%) and 1 (4%) and 3 (7%) and 1 (4%) children in the levocetirizine dihydrochloride and placebo-treated groups, respectively.

Long-Term Clinical Trials Experience

In two controlled clinical trials, 428 patients (190 males and 238 females) aged 12 years and older were treated with levocetirizine dihydrochloride 5 mg once daily for 4 or 6 months. The patient characteristics and the safety profile were similar to that seen in the short-term studies. Ten (2.3%) patients treated with levocetirizine dihydrochloride discontinued because of somnolence, fatigue or asthenia compared to 2 (< 1%) in the placebo group.

There are no long term clinical trials in children below 12 years of age with allergic rhinitis or chronic idiopathic urticaria.

Laboratory Test Abnormalities

Elevations of blood bilirubin and transaminases were reported in < 1% of patients in the clinical trials. The elevations were transient and did not lead to discontinuation in any patient.

Risk Summary

Available data from published literature and postmarketing experience with levocetirizine use in pregnant women are insufficient to identify any drug-associated risks of miscarriage, birth defects, or adverse maternal or fetal outcomes. In animal reproduction studies, there was no evidence of fetal harm with administration of levocetirizine by the oral route to pregnant rats and rabbits, during the period of organogenesis, at doses up to 390 times and 470 times, respectively, the maximum recommended human dose (MRHD) in adults. In rats treated during late gestation and the lactation period, cetirizine had no effects on pup development at oral doses up to approximately 60 times the MRHD in adults. In mice treated during late gestation and the lactation period, cetirizine administered by the oral route to the dams had no effects on pup development at a dose that was approximately 25 times the MRHD in adults; however, lower pup weight gain during lactation was observed at a dose that was 95 times the MRHD in adults [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data

Risk Summary

There are no data on the presence of levocetirizine in human milk, the effects on the breastfed infant, or the effects on milk production. However, cetirizine has been reported to be present in human breast milk. In mice and beagle dogs, studies indicated that cetirizine was excreted in milk (see Data). When a drug is present in animal milk, it is likely the drug will be present in human milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for levocetirizine dihydrochloride and any potential adverse effects on the breastfed child from levocetirizine dihydrochloride or from the underlying maternal condition.

Data

Absorption

Levocetirizine is rapidly and extensively absorbed following oral administration. In adults, peak plasma concentrations are achieved 0.9 hour after administration of the oral tablet. The accumulation ratio following daily oral administration is 1.12 with steady state achieved after 2 days. Peak concentrations are typically 270 ng/mL and 308 ng/mL following a single and a repeated 5 mg once daily dose, respectively. Food had no effect on the extent of exposure (AUC) of the levocetirizine tablet, but Tmax was delayed by about 1.25 hours and Cmax was decreased by about 36% after administration with a high fat meal; therefore, levocetirizine can be administered with or without food.

A dose of 5 mg (10 mL) of levocetirizine dihydrochloride oral solution is bioequivalent to a 5 mg dose of levocetirizine dihydrochloride tablets. Following oral administration of a 5 mg dose of levocetirizine dihydrochloride oral solution to healthy adult subjects, the mean peak plasma concentrations were achieved approximately 0.5 hour post dose.

Distribution

The mean plasma protein binding of levocetirizine in vitro ranged from 91 to 92%, independent of concentration in the range of 90 ng/mL to 5,000 ng/mL, which includes the therapeutic plasma levels observed. Following oral dosing, the average apparent volume of distribution is approximately 0.4 L/kg, representative of distribution in total body water.

Metabolism

The extent of metabolism of levocetirizine in humans is less than 14% of the dose and therefore differences resulting from genetic polymorphism or concomitant intake of hepatic drug metabolizing enzyme inhibitors are expected to be negligible. Metabolic pathways include aromatic oxidation, N- and O-dealkylation, and taurine conjugation. Dealkylation pathways are primarily medicated by CYP3A4 while aromatic oxidation involves multiple and/or unidentified CYP isoforms.

Elimination

The plasma half-life in adult healthy subjects was about 8 to 9 hours after administration of oral tablets and oral solution, and the mean oral total body clearance for levocetirizine was 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. Renal clearance of levocetirizine correlates with that of creatinine clearance. In patients with renal impairment the clearance of levocetirizine is reduced [see Dosage and Administration (2.2)].

Drug Interaction Studies

In vitro data on metabolite interaction indicate that levocetirizine is unlikely to produce, or be subject to metabolic interactions. Levocetirizine at concentrations well above Cmax level achieved within the therapeutic dose ranges is not an inhibitor of CYP isoenzymes 1A2, 2C9, 2C19, 2A1, 2D6, 2E1, and 3A4, and is not an inducer of UGT1A or CYP isoenzymes 1A2, 2C9 and 3A4.

No formal in vivo drug interaction studies have been performed with levocetirizine. Studies have been performed with the racemic cetirizine [see Drug Interactions (7)].

Adults and Adolescents 12 Years of Age and Older

The efficacy of levocetirizine dihydrochloride was evaluated in four randomized, placebo-controlled, double-blind clinical trials in adult and adolescent patients 12 years and older with symptoms of perennial allergic rhinitis. The four clinical trials include two dose-ranging trials of 4 weeks duration and two efficacy trials (one 6-week and one 6-month) in patients with perennial allergic rhinitis.

These trials included a total of 1,729 patients (752 males and 977 females) of whom 227 were adolescents 12 to 17 years of age. Efficacy was assessed using a total symptom score from patient recording of 4 symptoms (sneezing, rhinorrhea, nasal pruritus, and ocular pruritus) in three studies and 5 symptoms (sneezing, rhinorrhea, nasal pruritus, ocular pruritus, and nasal congestion) in one study. Patients recorded symptoms using a 0 to 3 categorical severity scale (0 = absent, 1 = mild, 2 = moderate, 3 = severe) once daily in the evening reflective of the 24 hour treatment period. The primary endpoint was the mean total symptom score averaged over the first week and over 4 weeks for perennial allergic rhinitis trials.

The two dose-ranging trials were conducted to evaluate the efficacy of levocetirizine dihydrochloride 2.5 mg, 5 mg, and 10 mg once daily in the evening. These trials were 4 weeks in duration and included patients with perennial allergic rhinitis. In these trials, each of the three doses of levocetirizine dihydrochloride demonstrated greater decrease in the reflective total symptom score than placebo and the difference was statistically significant for all three doses in the two studies. Results for one of these trials are shown in Table 4.

One clinical trial evaluated the efficacy of levocetirizine dihydrochloride 5 mg once daily in the evening compared to placebo in patients with perennial allergic rhinitis over a 6-week treatment period. Another trial conducted over a 6-month treatment period assessed efficacy at 4 weeks. Levocetirizine dihydrochloride 5 mg demonstrated a greater decrease from baseline in the reflective total symptom score than placebo and the difference from placebo was statistically significant. Results of the former are shown in Table 5.

Onset of action was evaluated in two environmental exposure unit studies in allergic rhinitis patients with a single dose of levocetirizine dihydrochloride 2.5 mg or 5 mg. Levocetirizine dihydrochloride 5 mg was found to have an onset of action 1 hour after oral intake. Onset of action was also assessed from the daily recording of symptoms in the evening before dosing in the allergic rhinitis trials. In these trials, onset of effect was seen after 1 day of dosing.

Pediatric Patients Less than 12 Years of Age

There are no clinical efficacy trials with levocetirizine dihydrochloride 2.5 mg once daily in pediatric patients under 12 years of age, and no clinical efficacy trials with levocetirizine dihydrochloride 1.25 mg once daily in pediatric patients 6 months to 5 years of age. The clinical efficacy of levocetirizine dihydrochloride in pediatric patients under 12 years of age has been extrapolated from adult clinical trials based on pharmacokinetic comparisons [see Use in Specific Populations (8.4)].

Adult Patients 18 Years of Age and Older

The efficacy of levocetirizine dihydrochloride for the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria was evaluated in two multi-center, randomized, placebo-controlled, double-blind clinical trials of 4 weeks duration in adult patients 18 to 85 years of age with chronic idiopathic urticaria. The two trials included one 4-week dose-ranging trial and one 4-week single-dose level efficacy trial. Thee trails included 423 patients (139 males and 284 females). Most patients (> 90%) were Caucasian and the mean age was 41. Of these patients, 146 recieved levocetirizine dihydrochloride 5 mg once daily in the evening. Efficacy was assessed based on patient recording of pruritus severity on a severity score of 0 to 3 (0 = none to 3 = severe). The primary efficacy endpoint was the mean reflective pruritis severity score over the first week and over the entire treatment period. Additional efficacy variables were the instantaneous pruritis severity score, the number and size of wheals, and duration of pruritus.

The dose-ranging trial was conducted to evaluate the efficacy of levocetirizine dihydrochloride 2.5 mg, 5 mg, and 10 mg once daily in the evening. In this trial, each of the three doses of levocetirizine dihydrochloride demonstrated greater decrease in the reflective pruritis severity score than placebo and the difference was statistically significant for all three doses (see Table 6)

The single dose level trial evaluated the efficiency of levocetirizine dihydrochloride 5 mg once daily in the evening compared to placebo in patients with chronic idiopathic urticaria over a 4-week treatment period.

Levocetirizine dihydrochloride 5 mg demonstrated a greater decrease from baseline in the reflective pruritis severity score than placebo and the difference from placebo was statistically significant.

Duration of pruritus, number and size of wheals, and instantaneous pruritus severity score also showed significant improvement over placebo. The significant improvement in the instantaneous pruritis severity score over placebo confirmed end of dosing interval efficacy (see Table 6).

Pediatric Patients

There are no clinical efficacy trials in pediatric patients with chronic idiopathic urticaria [see Use in Specific Populations (8.4)].