CONTRAINDICATIONS
Cetirizine is contraindicated in those patients with a known hypersensitivity to it or any of
its ingredients or hydroxyzine.
PRECAUTIONS
Activities Requiring Mental Alertness: In clinical trials, the occurrence of somnolence
has been reported in some patients taking cetirizine; due caution should therefore be
exercised when driving a car or operating potentially dangerous machinery. Concurrent
use of cetirizine with alcohol or other CNS depressants should be avoided because
additional reductions in alertness and additional impairment of CNS performance may
occur.
Carcinogenesis, Mutagenesis, and Impairment of Fertility: In a 2-year carcinogenicity
study in rats, cetirizine was not carcinogenic at dietary doses up to 20 mg/kg
(approximately 15 times the maximum recommended daily oral dose in adults on a mg/m2
basis, or approximately 10 times the maximum recommended daily oral dose in children
on a mg/m2 basis). In a 2-year carcinogenicity study in mice, cetirizine caused an
increased incidence of benign liver tumors in males at a dietary dose of 16 mg/kg
(approximately 6 times the maximum recommended daily oral dose in adults on a mg/m2
basis, or approximately 4 times the maximum recommended daily oral dose in children on
a mg/m2 basis). No increase in the incidence of liver tumors was observed in mice at a
dietary dose of 4 mg/kg (approximately 2 times the maximum recommended daily oral
dose in adults on a mg/m2 basis, or approximately equal to the maximum recommended
daily oral dose in children on a mg/m2 basis). The clinical significance of these findings
during long-term use of cetirizine is not known.
Cetirizine was not mutagenic in the Ames test, and not clastogenic in the human
lymphocyte assay, the mouse lymphoma assay, and in vivo micronucleus test in rats.
In a fertility and general reproductive performance study in mice, cetirizine did not impair
fertility at an oral dose of 64 mg/kg (approximately 25 times the maximum recommended
daily oral dose in adults on a mg/m2 basis).
Pregnancy Category B: In mice, rats, and rabbits, cetirizine was not teratogenic at oral
doses up to 96, 225, and 135 mg/kg, respectively (approximately 40, 180 and 220 times
the maximum recommended daily oral dose in adults on a mg/m2 basis). There are no
adequate and well-controlled studies in pregnant women. Because animal studies are not
always predictive of human response, cetirizine should be used in pregnancy only if
clearly needed.
Nursing Mothers: In mice, cetirizine caused retarded pup weight gain during lactation at
an oral dose in dams of 96 mg/kg (approximately 40 times the maximum recommended
daily oral dose in adults on a mg/m2 basis). Studies in beagle dogs indicated that
approximately 3% of the dose was excreted in milk. Cetirizine has been reported to be
excreted in human breast milk. Because many drugs are excreted in human milk, use of
cetirizine in nursing mothers is not recommended.
Geriatric Use: In placebo-controlled trials, 186 patients aged 65 to 94 years received
doses of 5 to 20 mg of cetirizine per day. Adverse events were similar in this group to
patients under age 65. Subset analysis of efficacy in this group was not done.
Pediatric Use: The safety of cetirizine, at daily doses of 5 or 10 mg, has been
demonstrated in 376 pediatric patients aged 6 to 11 years in placebo-controlled trials
lasting up to four weeks and in 254 patients in a non-placebo-controlled 12-week trial.
The safety of cetirizine has been demonstrated in 168 patients aged 2 to 5 years in
placebo-controlled trials of up to 4 weeks duration. On a mg/kg basis, most of the 168
patients received between 0.2 and 0.4 mg/kg of cetirizine HCl.
The effectiveness of cetirizine for the treatment of seasonal and perennial allergic rhinitis
and chronic idiopathic urticaria in pediatric patients aged 2 to 11 years is based on an
extrapolation of the demonstrated efficacy of cetirizine in adults in these conditions and
the likelihood that the disease course, pathophysiology and the drug's effect are
substantially similar between these two populations. The recommended doses for the
pediatric population are based on cross-study comparisons of the pharmacokinetics and
pharmacodynamics of cetirizine in adult and pediatric subjects and on the safety profile of
cetirizine in both adult and pediatric patients at doses equal to or higher than the
recommended doses. The cetirizine AUC and Cmax in pediatric subjects aged 2 to 5
years who received a single dose of 5 mg of cetirizine syrup and in pediatric subjects
aged 6 to 11 years who received a single dose of 10 mg of cetirizine syrup were
estimated to be intermediate between that observed in adults who received a single dose
of 10 mg of cetirizine tablets and those who received a single dose of 20 mg of cetirizine
tablets.
The safety and effectiveness of cetirizine in pediatric patients under the age of 2 years
have not yet been established.