Adult: Available preparation:
Cetirizine 5 mg and pseudoephedrine 120 mg
As extended-release tab: 1 tab bid. Child: ≥12 years Same as adult dose. Elderly: Limit cetirizine dose to 5 mg once daily.
1 tab once daily.
1 tab once daily.
extended-release: May be taken with or without food. Swallow whole, do not chew/crush.
Narrow angle glaucoma, urinary retention, severe hypertension, severe coronary artery disease. Children below 12 years. Concomitant or within 14 days of MAOI use.
Patient with CV disease (e.g. hypertension, ischaemic heart disease), diabetes mellitus, increased intraocular pressure, thyroid dysfunction, urinary obstruction (including prostatic hypertrophy). Renal and hepatic impairment. Elderly. Treatment with cold medicines in children should be considered carefully due to potential risks and limited evidence on efficacy. Pregnancy and lactation.
Significant: CNS stimulation or depression, CV collapse with hypotension. Cardiac disorders: Tachycardia, palpitation. Gastrointestinal disorders: Dry mouth, nausea. General disorders and administration site conditions: Asthenia, restlessness, weakness, ataxia. Metabolism and nutrition disorders: Anorexia. Nervous system disorders: Headache, dizziness, vertigo, convulsions. Psychiatric disorders: Insomnia, anxiety, fear, nervousness, hallucinations, dysphonia. Renal and urinary disorders: Dysuria. Respiratory, thoracic and mediastinal disorders: Respiratory difficulty, epistaxis, pharyngitis. Vascular disorders: Pallor.
This drug may cause CNS depression (e.g. somnolence), if affected, do not drive or operate machinery.
Symptoms: Hypertension, arrhythmia, tachycardia, CNS depression (e.g. sedation, cyanosis, apnoea, unconsciousness, CV collapse) or stimulation (hallucinations, tremor, seizures, insomnia). Management: Symptomatic and supportive treatment. Induce vomiting or employ gastric lavage. Diazepam may be given to manage seizures. Hypertension may be treated with α-blockers and tachycardia with β-blockers.
Increased pharmacological effect with CNS depressants.
Pseudoephedrine: Increased ectopic pacemaker activity may occur when given with digitalis. May decrease pharmacological effect of antihypertensive agents that interfere with sympathetic activity (e.g. reserpine, methyldopa). Potentially Fatal: Hypertensive crisis may result when pseudoephedrine is given with MAOIs.
Increased CNS depression with alcohol.
Description: Cetirizine is an antihistamine which competitively and selectively inhibits H1 receptors in the gastrointestinal and respiratory tract and blood vessels.
Pseudoephedrine is a sympathomimetic agent which has a decongestant action on the nasal mucosa. It directly stimulates α- and β-adrenergic receptors thereby causing vasoconstriction of respiratory mucosa, relaxation of bronchial muscles and increased heart rate and contractility. Pharmacokinetics: Absorption: Cetirizine: Rapidly absorbed from the gastrointestinal tract. Time to peak plasma concentration: 2.2 hours.
Pseudoephedrine: Readily absorbed from the gastrointestinal tract. Time to peak plasma concentration: 4.4 hours. Distribution: Enters breast milk.
Cetirizine: Plasma protein binding: 93%.
Pseudoephedrine: Volume of distribution: 2.6-3.3 L/kg. Metabolism: Cetirizine: Metabolised via oxidative O-dealkylation.
Pseudoephedrine: Minimally metabolised via N-demethylation to norpseudoephedrine. Excretion: Cetirizine: Mainly via urine (70%, approx 50% as unchanged drug); faeces (10%). Elimination half-life: 7.9 hours.
Pseudoephedrine: Mainly via urine as unchanged drug and as metabolites. Elimination half-life: 6 hours.