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Each prolonged release tablet contains 5 mg cetirizine dihydrochloride and 120 mg pseudoephedrine hydrochloride.

Prolonged release tablet
White to off-white, round biconvex tablet

Pharmacodynamic properties
The pharmacodynamic activity of ZYRTEC-D (ATC code R01B A52) is directly related to an additive effect of the activity of each of its components. Cetirizine is a potent and selective H1-receptor antagonist with additional anti-allergic properties: it inhibits the histamine-related early phase of the allergic reaction and also reduces the migration of certain inflammatory cells and the release of certain mediators associated with the late allergic response; it inhibits the histamine or pollen-induced reactions in nasal provocation tests.

Pseudoephedrine is an orally active sympathomimetic amine with alpha-mimetic activity predominating over beta-mimetic activity; due to its vasoconstrictor action, it has a decongestant effect on the nasal mucosa.

Pharmacokinetic properties
After oral administration, cetirizine is rapidly and almost completely absorbed. Maximal plasma concentrations are generally obtained within 1 hour under fasting conditions. Cetirizine does not undergo any appreciable first pass metabolism. After repeated oral administration, the daily urinary excretion of unchanged cetirizine is approximately 65% of the dose. The absorption and the elimination of cetirizine are independent of the dose. Inter- and intra-subjects variations are low. The plasma half-life of cetirizine is approximately 9 hours. This value is increased in patients with reduced renal function.

Cetirizine is highly bound to plasma proteins (93%). Its volume of distribution is small: approximately 0.5 l/kg.

Pseudoephedrine given as the sustained-release formulation ZYRTEC-D provides maximum plasma levels 2 to 6 hours after multiple dosing. It is excreted mainly unchanged in the urine. The rate of urinary excretion is increased when the pH of urine is reduced, and reduced in case of alkalinization of urine. After repeated oral administration (every 12 hours), at steady-state, the apparent elimination half-life is estimated to be approximately 9 hours.

A high fat meal was not found to modify the bioavailability of both active ingredients, but it resulted however in a reduced and delayed peak plasma concentration of cetirizine. There was no evidence for a relevant pharmacokinetic interaction between cetirizine and pseudoephedrine.

The dose should be reduced to half the usual recommended dose in patients with renal insufficiency.

Therapeutic indications
ZYRTEC-D is indicated for the treatment of symptoms associated with seasonal and perennial allergic rhinitis such as nasal congestion, sneezing, rhinorrhea, nasal and ocular pruritus. It should be administered when both the antiallergic properties of cetirizine dihydrochloride and the nasal decongestant activity of pseudoephedrine hydrochloride are desired.

Posology and method of administration
Adults and children aged 12 years and older: one tablet twice daily (morning and evening), with or without food. The tablets should be swallowed with some liquid and should not be chewed or crushed.

The duration of treatment should not exceed the period of symptoms, and should not exceed 2 to 3 weeks. When adequate relief from nasal symptoms is obtained, treatment with cetirizine should be continued, if appropriate.

In patients with moderate renal or hepatic insufficiency, dosage should be reduced to one tablet per day.


ZYRTEC-D is contra-indicated:
in cases of known hypersensitivity to one of its ingredients, to ephedrine or any other piperazine
in cases of severe hypertension or severe coronary artery disease
in patients receiving dihydroergotamine

in cases of severe renal insufficiency, uncontrolled hyperthyroidism, severe arrhythmias, pheochromocytoma, elevated intraocular pressure or urinary retention
during treatment with monoamine oxidase (MAO) inhibitor and also for 2 weeks after their discontinuation.
in patients with a history of stroke
or in patients at high risk of developing haemorrhagic stroke

ZYRTEC-D is not recommended in children under 12 years of age as it has not been studied in this age group.

Special warnings and special precautions for use
Due to the presence of pseudoephedrine, ZYRTEC-D should be used with caution in patients with diabetes mellitus, hyperthyroidism, arterial hypertension, tachycardia, cardiac arrhythmia, ischemic heart disease, moderate renal or hepatic insufficiency, and in the elderly.

Caution is also required in patients taking:
- sympathomimetic drugs such as decongestants, appetite suppressants, psychostimulants such as amphetamines (combined effects on the cardiovascular system)
- tricyclic antidepressants
- antihypertensive drugs (reduction of antihypertensive effects)
- alcohol or other CNS depressants (enhanced CNS depression and impaired performance)
- digitalis (risk of cardiac arrhythmia)
- as well as in conditions where anticholinergic activity is undesirable, such as prostatic hypertrophy or bladder outflow obstruction.

Caution should also be exercised in patients with factors which could increase the risk of haemorrhagic stroke, as concomitant use of vasoconstrictors such as bromocriptine, pergolide, lisuride, cabergoline, ergotamine, or any other decongestant drug used as nasal decongestant, either by oral route or by nasal route (phenylpropanolamine, phenylephrine, ephedrine), due to the risk of vasoconstriction and increased blood pressure.

Due to vasoconstrictor effect of pseudoephedrine, caution is recommended in patients who are at risk for hypercoagulabiliy, as in inflammatory bowel disease.


Caution is required in hypertensive patients who are treated concomitantly with NSAIDs, because both pseudoephedrine and NSAIDs can increase blood pressure.

As for other centrally acting stimulants, abuse has been observed for pseudoephedrine.

Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Interaction with other medicinal products and other forms of interaction
Pharmacokinetic interaction studies were conducted with cetirizine and cimetidine, ketoconazole, erythromycin, azithromycin and pseudoephedrine; no pharmacokinetic interactions were observed.


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, 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 not altered by concomitant cetirizine administration.

Concomitant use of symphatomimetic amines with monoamine oxidase (MAO) inhibitors can result in hypertensive crisis. Because of the long duration of action of MAO inhibitors, this interaction is still possible 15 days after stopping such a treatment.

Sympathomimetic amines may reduce the antihypertensive effects of betaadrenergic blockers and of drugs that interfere with sympathetic activity such as methyldopa, guanethidine and reserpine; (see Special Warnings).


Administration of linezolid with pseudoephedrine may result in an increase in blood pressure in normotensive patients.


Increased ectopic pacemaker activity can occur when pseudoephedrine is used concomitantly with digitalis; use of ZYRTEC-D is therefore to be avoided in digitalized patients.

Antacids and proton pump inhibitors increase the rate of pseudoephedrine absorption; kaolin decreases it.

Concurrent use with halogenated anaesthetic agents may provoke or worsen ventricular arrhythmia.

Allergy skin tests are inhibited by antihistamines and an appropriate wash-out period is required before performing them.


A high fat meal was not found to modify the bioavailability of both active ingredients, but it resulted however in a reduced and delayed peak plasma concentration of cetirizine.

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