New Zealand - English - Medsafe (Medicines Safety Authority)
NEW ZEALAND DATA SHEET
Zista, 10 mg, tablets
QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 10 mg cetirizine hydrochloride.
Excipient with known effect:
For the full list of excipients, see section 6.1.
White to off white capsule shaped film coated tablets with breakline on one side and ‘10’ embossed
on the other side.
Cetirizine is indicated for the relief of symptoms associated with seasonal allergic rhinitis (hay fever)
and perennial allergic rhinitis. Symptoms treated effectively include sneezing, rhinorrhea, post-nasal
discharge, nasal pruritus, ocular pruritus and tearing.
Cetirizine is also indicated for the treatment of:
insect bites and the uncomplicated skin manifestations of chronic idiopathic urticaria. It
significantly reduces the occurrence, severity and duration of hives and markedly reduces
Dose and method of administration
The recommended initial dose of cetirizine is 5 to 10 mg depending on symptom severity, given as a
single daily dose with or without food. The time of administration may be varied to suit individual
patient needs. If sufficient response is not obtained, the dose may be increased to the maximum
recommended daily dose of 20 mg.
Children aged 6-12 years
Same dose as for adults given as a single or divided dose.
Children aged 2-6 years
The recommended dose of cetirizine is 5 mg (half a tablet) once daily.
Use in Elderly
Data does not suggest that the dose needs to be reduced in elderly subjects provided that the renal
function is normal.
The dosing intervals must be individualised according to renal function.
Refer to the following table and adjust the dose as indicated. To use this dosing table, an estimate of
the patient’s creatinine clearance (CLcr) in mL/min is needed. The CLcr (mL/min) may be estimated
from serum creatinine (mg/dl) determination using the following formula:
[140 – age(years)] x weight (kg)
(x 0.85 for women)
72 x serum creatinine (mg/dl)
Dosing adjustments for adult patients with impaired renal function
Dosage and frequency
10 mg once daily
50 - 79
10 mg once daily
30 – 49
5 mg once daily
5 mg once every 2 days
End-stage renal disease –
Patients undergoing dialysis
In paediatric patients suffering from renal impairment, the dose will have to be adjusted on an
individual basis taking into account the renal clearance of the patient and body weight.
No dose adjustment is needed in patients with solely hepatic impairment.
Cetirizine hydrochloride is contraindicated in:
patients with a history of hypersensitivity to any of the constituents of the formulation, to
hydroxyzine or to any piperazine derivatives
patients with end stage renal impairment at less than 10 mL/min creatinine clearance.
Special warnings and precautions for use
At therapeutic doses, no clinically significant interactions have been demonstrated with alcohol (for a
blood alcohol level of 0.5 g/L). Nevertheless, precaution is recommended if alcohol is taken
Caution should be taken in patients with predisposition factors of urinary retention (eg. spinal cord
lesion, prostatic hyperplasia) as cetirizine may increase the risk of urinary retention.
Patients at risk of convulsions
Caution in epileptic patients and patients at risk of convulsions is recommended.
Pruritus and/or urticaria may occur when cetirizine is stopped, even if those symptoms were not
present before treatment initiation. In some cases, the symptoms may be intense and may require
treatment to be restarted. The symptoms should resolve when the treatment is restarted.
Interaction with other medicines and other forms of interaction
Pharmacokinetic interaction studies were conducted with cetirizine and pseudoephedrine, antipyrine,
cimetidine, ketoconazole, erythromycin, and azithromycin; no pharmacokinetic interactions were
In a multiple dose study of theophylline (400 mg once a day) and cetirizine, there was a small (16%)
decrease in clearance of cetirizine, while the disposition of theophylline was not altered by
concomitant cetirizine administration.
Studies with cetirizine and cimetidine, glipizide, diazepam, and pseudoephedrine have revealed no
evidence of adverse pharmacodynamic interactions.
Studies with cetirizine and azithromycin, erythromycin, ketoconazole, theophylline, antypirine, and
pseudoephedrine have revealed no evidence of adverse clinical interactions.
In particular, concomitant administration of cetirizine with macrolides or ketoconazole has never
resulted in clinically relevant ECG changes.
In a multiple dose study of ritonavir (600 mg twice daily) and cetirizine (10 mg daily), the extent of
exposure to cetirizine was increased by about 40% while the disposition of ritonavir was slightly
altered (-11%) further to concomitant cetirizine administration.
The extent of absorption of cetirizine is not reduced with food, although the rate of absorption is
decreased by 1 hour.
Allergy skin test
Allergy skin tests are inhibited by antihistamines and a wash-out period of 3 days is recommended
before performing them.
Fertility, pregnancy and lactation
Use in pregnancy (Category B2)
Caution should be exercised in pregnant women.
For cetirizine, very rare clinical data on exposed pregnancies are available. Animal studies do not
indicate direct or indirect harmful effects with respect to pregnancy, embryonal/foetal development,
parturition or postnatal development.
Use in lactation
Caution should be exercised in lactating women.
Cetirizine is excreted in human milk at concentrations representing 0.25 to 0.90 those measured in
plasma, depending on sampling time after administration.
Effects on ability to drive and use machines
Objective measurements of driving ability, sleep latency and assembly line performance have not
demonstrated any clinically relevant effects at the recommended dose of 10 mg.
Patients intending to drive, engaging in potentially hazardous activities or operating machinery should
not exceed the recommended dose and should take their response to the medicinal product into
In sensitive patients, concurrent use with alcohol or other CNS antidepressants may cause additional
reductions in alertness and impairment of performance.
Clinical Trial Data
Clinical studies have shown that cetirizine at the recommended dosage has minor adverse effects on
the CNS, including somnolence, fatigue, dizziness and headache.
In some cases, paradoxical CNS stimulation has been reported.
Although cetirizine is a selective antagonist of peripheral H1-receptors and is relatively free of
anticholinergic activity, isolated cases of micturition difficulty, eye accommodation disorders and dry
mouth have been reported.
Instances of abnormal hepatic function with elevated hepatic enzymes accompanied by elevated
bilirubin have been reported. Mostly this resolves upon discontinuation of the drug.
Double blind controlled clinical trials comparing cetirizine to placebo or other antihistamines at the
recommended dosage (10 mg daily for cetirizine), of which quantified safety data are available,
included more than 3200 subjects exposed to cetirizine.
From this pooling, the following adverse reactions were reported for cetirizine 10 mg in the placebo-
controlled trials at rates of 1.0% or greater:
Cetirizine 10 mg
(n = 3061)
Body as a whole – general disorders:
Central and peripheral nervous system disorders:
Gastrointestinal system disorders:
Respiratory system disorders:
Although statistically more common than under placebo, somnolence was mild to moderate in the
majority of cases. Objective tests as demonstrated by other studies have demonstrated that usual daily
activities are unaffected at the recommended daily dose in healthy young volunteers.
Adverse drug reactions at rates of 1 % or greater in children aged from 6 months to 12 years, included
in placebo-controlled clinical or pharmacoclinical trials are:
Adverse drug reactions
Gastrointestinal system disorders:
Respiratory system disorders:
Body as a whole – general disorders:
In addition to the adverse effects reported during clinical studies and listed above, isolated cases of the
following adverse drug reactions have been reported in post-marketing experience.
Undesirable effects are described according to MedDRA System Organ Class and by estimated
frequency based on post-marketing experience.
Frequencies are defined as follows: Very common (≥1/10); common (≥1/100 to <1/10); uncommon
(≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be
estimated from the available data)
Blood and lymphatic disorders:
Very rare: thrombocytopenia
Immune system disorders:
Very rare: anaphylactic shock
Metabolism and nutrition disorders:
Not known: increased appetite
Rare: aggression, confusion, depression, hallucination, insomnia
Very rare: tics
Not known: suicidal ideation
Nervous system disorders:
Very rare: dysgeusia, syncope, tremor, dystonia, dyskinesia
Not known: amnesia, memory impairment
Very rare: accommodation disorder, blurred vision, oculogyration
Rare: hepatic function abnormal (increased transaminases, alkaline phosphatase, gamma-
glutamyltransferase and bilirubin)
Skin and subcutaneous tissue disorders:
Uncommon: pruritus, rash
Very rare: angioneurotic oedema, drug eruption
Not known: acute generalized exanthematous pustulosis (AGEP)
Renal and urinary disorders:
Very rare: dysuria, enuresis
Not known: urinary retention
General disorders and administration site conditions:
Uncommon: asthenia, malaise
Rare: weight increased
Description of selected adverse reactions:
After discontinuation of cetirizine, pruritus (intense itching) and/or urticaria have been reported.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicine is important. It allows
continued monitoring of the benefit/risk balance of the medicine. Healthcare professionals are asked
to report any suspected adverse reactions (https://nzphvc.otago.ac.nz/reporting/).
Symptoms and signs
Symptoms observed after an overdose of cetirizine are mainly associated with CNS effects or with
effects that could suggest an anticholinergic effect.
Adverse events reported after an intake of at least 5 times the recommended daily dose are: confusion,
diarrhoea, dizziness, fatigue, headache, malaise, mydriasis, pruritus, restlessness, sedation,
somnolence, stupor, tachycardia, tremor, and urinary retention.
There is no known specific antidote to cetirizine.
Should overdose occur, symptomatic or supportive treatment is recommended. Gastric lavage should
be considered following ingestion of a short occurrence.
Cetirizine is not effectively removed by dialysis.
For advice on the management of overdose please contact the National Poisons Centre on 0800
POISON (0800 764766).
Pharmacotherapeutic group: Antihistamine for systemic use, piperazine derivatives, ATC code:
Cetirizine, a human metabolite of hydroxyzine, is a potent and selective antagonist of peripheral H
receptors. In vitro receptor binding studies have shown no measurable affinity for other than H1-
Ex vivo experiments in mice have shown that systemically administered cetirizine does not
significantly occupy the cerebral H1-receptors.
In addition to its anti-H1 effect, cetirizine was shown to display anti-allergic activities: at a dose of 10
mg once or twice daily, it inhibits the late phase recruitment of inflammatory cells, notably
eosinophils, in the skin and conjunctiva of atopic subjects submitted to antigen challenge, and the
dose of 30 mg/day inhibits the influx of eosinophils in the bronchoalveolar lavage fluid during a late-
phase bronchial constriction induced by allergen inhalation in asthmatic subjects. Moreover,
cetirizine inhibits the late-phase inflammatory reaction induced in chronic urticaria patients by
intradermal administration of kallikrein. It also down regulates the expression of adhesion molecules,
such as ICAM-1 and VCAM-1, which are markers of allergic inflammation.
Studies in healthy volunteers show that cetirizine at doses of 5 and 10 mg strongly inhibits the wheal
and flare reactions induced by very high concentrations of histamine into the skin. The onset of
activity after a single 10 mg dose occurs within 20 minutes in 50% of the subjects and within one hour
in 95%. This activity persists for at least 24 hours after a single administration. In a 35 day study in
children aged 5 to 12, no tolerance to the antihistaminic effect (suppression of wheal and flare) of
cetirizine was found. When a treatment with cetirizine is stopped after repeated administration, the
skin recovers its normal reactivity to histamine within 3 days.
Cetirizine exhibits linear kinetics over the range of 5 to 60 mg. The terminal half-life is
approximately 10 hours and the apparent volume of distribution is 0.50 l/kg.
No accumulation is observed for cetirizine following daily doses of 10 mg for 10 days. The steady –
state maximum plasma concentration is approximately 300 ng/mL and is achieved within 1.0±0.5 h.
Plasma protein binding of cetirizine is 93±0.3%.
Cetirizine does not modify the protein binding of warfarin.
Cetirizine does not undergo extensive first pass metabolism. About two thirds of the dose are
excreted unchanged in the urine.
The distribution of pharmacokinetic parameters as peak level and area under curve, is unimodal in
human volunteer and no differences were observed in the kinetics of cetirizine between white and
black adult males. The extent of absorption of cetirizine is not reduced with food, although the rate of
absorption is decreased. The extent of bioavailability is similar when cetirizine is given as solutions,
capsules or tablets.
Preclinical safety data
Non-clinical data reveal no special hazard for humans based on conventional studies of safety
pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, toxicity to reproduction.
List of excipients
Maize starch, lactose monohydrate, pregelatinised starch, purified talc, Magnesium stearate. The film
coating contains hypromellose, purified talc, titanium dioxide (E171), macrogol 6000.
Contains lactose. Patients with rare hereditary problems of galactose intolerance, (the Lapp lactase
deficiency or glucose-galactose malabsorption) should not take this medicine.
Special precautions for storage
Store below 25°C.
Nature and contents of container
PVC/Aluminium foil blister strips. Pack size of 10, 30 and 100 tablets.
Special precautions for disposal
No special requirements for disposal.
Pharmacy Only Medicine
Teva Pharma (New Zealand) Limited
PO Box 128 244
Telephone: 0800 800 097
DATE OF FIRST APPROVAL
15 May 2014
DATE OF REVISION OF THE TEXT
5 June 2018
SUMMARY TABLE OF CHANGES
Summary of new information
Additional information on urinary retention and rebound
Additional safety information.