Cetirizine comes as a tablet, a chewable tablet, an extended release tablet, and a syrup (liquid) to take by mouth. It is usually taken once a day with or without food.
Cetirizine hydrochloride, is an orally active and selective H1-receptor antagonist. The chemical name is (±) – [2- [4- [ (4-chlorophenyl)phenylmethyl] -1- piperazinyl] ethoxy]acetic acid, dihydrochloride. Cetirizine hydrochloride is a racemic compound with an empirical formula of C21H25ClN2O3•2HCl.

The molecular weight is 461.82

Cetirizine USES

Seasonal Allergic Rhinitis:

This is indicated for the relief of symptoms associated with seasonal allergic rhinitis due to allergens such as ragweed, grass and tree pollens in adults and children 2 years of age and older. Symptoms treated effectively include sneezing, rhinorrhea, nasal pruritus, ocular pruritus, tearing, and redness of the eyes.

Perennial Allergic Rhinitis:

Cetrizine is indicated for the relief of symptoms associated with perennial allergic rhinitis due to allergens such as dust mites, animal dander and molds in adults and children 6 months of age and older. Symptoms treated effectively include sneezing, rhinorrhea, postnasal discharge, nasal pruritus, ocular pruritus, and tearing.

Chronic Urticaria:

Cetrizine is indicated for the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria in adults and children 6 months of age and older. It
significantly reduces the occurrence, severity, and duration of hives and significantly reduces pruritus.

Citrizine Adult and kids dosages

Tablet

5 mg
10 mg
Tablet, oral-disintegrating

10 mg
Tablet, chewable

5 mg
10 mg
Syrup

5 mg/5 ml
Solution

5 mg/5 ml
Geriatric

5 mg orally once per day, may increase to 10 mg per day maximum, depending on the severity of the symptoms, not to exceed 5 mg per day in patients over 77 years old

Cetrizine side effects

drowsiness
excessive tiredness
dry mouth
stomach pain
diarrhea
vomiting

Cetirizine Mechanism of Actions:

Cetirizine, a human metabolite of hydroxyzine, is an antihistamine; its principal effects are mediated via selective inhibition of peripheral H1 receptors. The
antihistaminic activity of cetirizine has been clearly documented in a variety of animal and human models. In vivo and ex vivo animal models have shown negligible anticholinergic and
antiserotonergic activity. In clinical studies, however, dry mouth was more common with cetirizine than with placebo. In vitro receptor binding studies have shown no measurable affinity
for other than H1 receptors. Autoradiographic studies with radiolabeled cetirizine in the rat have shown negligible penetration into the brain. Ex vivo experiments in the mouse have shown that
systemically administered cetirizine does not significantly occupy cerebral H1 receptors.

Cetirizine Pharmacokinetics:

Absorption:

Cetirizine was rapidly absorbed with a time to maximum concentration (Tmax) of approximately 1 hour following oral administration of tablets or syrup in adults. Comparable bioavailability was found between the tablet and syrup dosage forms. When healthy volunteers
were administered multiple doses of cetirizine (10 mg tablets once daily for 10 days), a mean peak plasma concentration (Cmax) of 311 ng/mL was observed. No accumulation was observed.
Cetirizine pharmacokinetics were linear for oral doses ranging from 5 to 60 mg. Food had no effect on the extent of cetirizine exposure (AUC) but Tmax was delayed by 1.7 hours and Cmax
was decreased by 23% in the presence of food.

Distribution:

The mean plasma protein binding of cetirizine is 93%, independent of concentration in the range of 25-1000 ng/mL, which includes the therapeutic plasma levels
observed.

Metabolism:

A mass balance study in 6 healthy male volunteers indicated that 70% of the administered radioactivity was recovered in the urine and 10% in the feces. Approximately 50%
of the radioactivity was identified in the urine as unchanged drug. Most of the rapid increase in peak plasma radioactivity was associated with parent drug, suggesting a low degree of first-pass
metabolism. Cetirizine is metabolized to a limited extent by oxidative O-dealkylation to a metabolite with negligible antihistaminic activity. The enzyme or enzymes responsible for this
metabolism have not been identified.

Elimination:

The mean elimination half-life in 146 healthy volunteers across multiple pharmacokinetic studies was 8.3 hours and the apparent total body clearance for cetirizine was
approximately 53 mL/min.

Interaction Studies
Pharmacokinetic interaction studies with cetirizine in adults were conducted withpseudoephedrine, antipyrine, ketoconazole, erythromycin and azithromycin. No interactions were
observed. In a multiple dose study of theophylline (400 mg once daily for 3 days) and cetirizine (20 mg once daily for 3 days), a 16% decrease in the clearance of cetirizine was observed. The
disposition of theophylline was not altered by concomitant cetirizine administration.

Trade names of Cetirizine

Cold tablet names in Telugu

Cetirizine is indicated for the relief of nasal and ocular symptoms of seasonal and perennial allergic rhinitis.
– Cetirizine is indicated for the relief of symptoms of chronic idiopathic urticaria.

Posology and method of administration
Children aged from 6 to 12 years: 5mg twice daily (a half tablet twice daily).
Adults and adolescents over 12 years of age: 10mg once daily (1 tablet)
The tablets need to be swallowed with a glass of liquid.

Cetrizine Overdose

Symptoms
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.
Management
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. Alternatively consider activated charcoal.
Cetirizine is not effectively removed by dialysis.

Safe Cold Flu Medications during Pregnancy & Breast Feeding

Breastfeeding mothers wonder whether some quick relief from over-the-counter medications could negatively impact their breastfeeding baby. When it comes to your baby no loss can be afforded if it poses even a negligible risk and therefore while taking medications for common cold flu, pregnant women are to follow special instructions. Research shows that some cold and flu medications are better than others when it comes to breastfeeding.
Here are some cold flu medications that are safe while breastfeeding.
The common active ingredients in cold and flu syrups are Dextromethorphan, acetaminophen, and doxylamine succinate along with their generic ingredients.

Dextromethorphan is a cough suppressant commonly used for treating colds in children and adults. It is generally considered safe while breastfeeding.
Acetaminophen, a drug used to treat pain and reduce fever in adults and children, works for pregnant women as well.
A common active ingredient in the nighttime formulations is doxylamine succinate, an antihistamine that causes sedation in its users and can be used for nausea and vomiting in pregnancy. This drug is considered safe while breastfeeding yet extensive study is going on.

Another fever reducer and pain medication naming Ibuprofen often used during a cold, also safe for infants of breastfeeding mothers. Even high maternal consumption of ibuprofen leads to very little excretion in breast milk.
Phenylephrine is most commonly used as a nasal decongestant in adults and children. It is generally considered safe while breastfeeding unless there has been high maternal consumption of the drug, and can cause tachycardia and hypertension in sensitive individuals as phenylephrine has poor oral bioavailability.
Pseudoephedrine, a nasal decongestant commonly used to treat colds, has shown to be secreted in breast milk in extremely low levels and is considered safe while breastfeeding.
During the cold and flu season, nasal sprays are additionally used. These include fluticasone and oxymetazoline (Afrin). Fluticasone is a steroid that is of intranasal use for congested noses and additionally for asthma. When using the medication as indicated, maternal plasma levels are undetectable. Thus, it is unlikely that a significant amount of this drug would pass into breastmilk to affect a breastfeeding infant. Oxymetazoline is another intranasal decongestant used quite frequently for runny noses. Due to the local effect of this drug, it is unlikely that significant levels of this drug would be transferred to a breastfeeding infant and is preferred over oral decongestants during breastfeeding. Oxymetazoline use should be limited to 3 days to avoid rebound congestion.
Vitamin C intake is effective for cold-fighting. Although its efficacy is still in research, it is likely not harmful to supplement while breastfeeding. Even high levels of maternal consumption resulted in only slightly increased levels in breastmilk.

Here is a table to classify the safety level of the medications as per data collected:-

Medication Breastfeeding Class Description
Acetaminophen L1 Extensive data. Compatible.
Dextromethorphan L1 Extensive data. Compatible.
Ibuprofen L1 Extensive data. Compatible.
Vitamin C L1 Limited data. Probably compatible.
Diphenhydramine L2 Limited data. Probably compatible.
Zinc Oxide L2 Limited data. Probably compatible.*
Zinc Salts L2 Limited data. Probably compatible.*
Doxylamine                                   L3 No data. Probably compatible.
Fluticasone L3 No data. Probably compatible.
Guaifenesin L3 No data. Probably compatible.
Ozymetazoline L3 No Data. Probably compatible.
Phenylephrine L3 No data. Probably compatible.
Pseudoephedrine L3 Limited data. Probably compatible
*Avoid early postnatal use when milk levels of zinc are high.