Claritin vs Zyrtec


Over-the-counter allergy relief medications Claritin and Zyrtec have similar effects but different groups of people react adversely to them. For example, if you use muscle relaxants, sleeping pills or other allergy medications, Zyrtec is not advisable. People suffering from liver disorders or PKU (phenylketonuria) should avoid Claritin. But Zyrtec and Claritin are both by and large equally effective as antihistamines i.e. in alleviating allergy symptoms.

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Active ingredient Loratadine Cetirizine
Treatment for Allergy such as hay fever (allergic rhinitis), urticaria (hives), and other skin allergies. Alleviates sneezing, runny nose, itchy or burning eyes. It also treats mild to moderate pain from headaches. Allergies, hay fever, angioedema, and urticaria.
Half-life 8 hours 8.3 Hours
Marketed by Schering-Plough Pfizer
Chemical Data Formula C22H23ClN2O2 Mol. Mass 382.88 g/mol Formula C21H25ClN2O3 Mol. Mass 388.89 g/mol
Systematic (IUPAC) name Ethyl 4-(8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylate (±)-[2-[4-[(4-chlorophenyl)phenylmethyl]-1- piperazinyl]ethoxy]acetic acid
Administration method Liquid syrup, tablets and tablets designed to dissolve in your mouth Liquid syrup, tablets and chewable tablets
Inform the doctor If you have severe hepatic (liver) disorders or PKU (a rare genetic syndrome called phenylketonuria) If you use muscle relaxers, sleeping pills or other allergy medications
Side effects Headache and antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastrointestinal disturbances Dryness of the mouth, nose and throat, drowsiness, urinary retention, blurred vision and stomach ache
Excretion 40% as conjugated metabolites into urine Similar amount into the feces Urine (mainly), hepatic or excrement (Small amounts)

Contents: Claritin vs Zyrtec

edit Allergies Treated

Zyrtec and Claritin both provide relief from hay fever (allergic rhinitis), urticaria (hives), angioedema and other skin allergies. It also treats allergic reactions like sneezing, runny nose, itchy or burning eyes caused by allergens in the environment or food allergy. It may also be prescribed for treating mild to moderate headaches.

In this video, Dr David H talks about relieving the symptoms of running nose due to allergies or cold for kids (ages 6 and under) as well as under:

The effectiveness of various antihistamines, as researched by Consumer Reports

edit Metabolism

The effect of Claritin peaks in 1–2 hours. Its half-life is 8 hours. Traces of Claritin remain in the body for approximately 28 hours. 40% is excreted as conjugated metabolites into the urine, and a similar amount is excreted into the feces. Traces of unmetabolised loratadine can be found in the urine.

The effects of Zyrtec start within about an hour. Zyrtec remains in the body for a maximum of 21 hours. Its half-life is 8.3 hours. 70% of the drug is removed through urination, of which half is observed as unchanged cetirizine compound. Another 10% is excreted.

2D structure of nonsedating antihistamine loratadine (Claritin)
2D structure of nonsedating antihistamine loratadine (Claritin)

edit Active Ingredients

edit Claritin

Loratadine is the active ingredient in Claritin. It is a second-generation H1 histamine antagonist. Its Systematic (IUPAC) name is Ethyl 4-(8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylate and its chemical formula is C22H23ClN2O2

Chemical structure of cetirizine (Zyrtec)
Chemical structure of cetirizine (Zyrtec)

edit Zyrtec

The active ingredient in Zyrtec is cetirizine. It is a second-generation antihistamine, is a major metabolite of hydroxyzine, and a racemic selective H1 receptor inverse agonist. Its Systematic (IUPAC) name is (±)-[2-[4-[(4-chlorophenyl)phenylmethyl]-1- piperazinyl]ethoxy]acetic acid and the chemical formula is C21H25ClN2O3.

edit Forms

Claritin is available in the form of tablets, oral suspension, syrup, and quick-dissolving tablets while Zyrtec is available in chewable, non-chewable, and syrup

edit Recommended Dosage

Age Group Claritin (Loratadine) Zyrtec (Cetirizine)
Adults & Children (>6yrs) 1 10 mg tablet/reditab, or 2 tbs (10 mg) of syrup once daily. 5 mg or 10 mg once daily
Children (2 to 5 yrs) 1 tsp (5 mg)once daily. 2.5 mg (½ teaspoon) syrup once daily. Max dose is 5 mg per day.
Children (6 mo to <2yrs) Not recommended 2.5 mg (½ teaspoon) once daily. For children 12-23 mo, max dose is 5 mg per day.
Adults & Children (>11yrs) with special condition (liver failure, renal or hepatic impairment) Start with 1 tablet or 2 tsp (10 mg) every other day. 5 mg once daily.
Children (6-11yrs) with special condition (liver failure, renal or hepatic impairment) Start with 1 tablet or 2 tsp (10 mg) every other day. Not recommended

edit Side Effects

edit Allergic reactions

Allergic reactions to Claritin or Zyrtec is rare. An allergic reaction to either of these drugs may incude hives, difficult breathing, swelling of your face, lips, tongue, or throat. It is recommended to seek medical help immediately in case of an allergic reaction.

edit Serious side effects

Serious side effects for Claritin may include fast or uneven heart rate; pass out feeling; jaundice (yellowing of your skin or eyes) or seizures (convulsions).

For Zyrtec, serious side effects include fast or uneven heart rate; weakness, tremors or insomnia; severe restlessness or hyperactivity; confusion; problems with vision; or urinating less than usual or not at all.

It is recommended to seek medical help immediately in case one or more serious side effects are seen.

A new side effect to these drugs may also be reported to US FDA at 1-800-FDA-1088 and Health Canada at 1-866-234-2345.

edit Less serious side effects

Less serious side effects to Claritin may include headache, nervousness, feeling tired or drowsy, stomach pain, diarrhea, dry mouth and sore throat.

For Zyrtec, less serious side effects may include dizziness, drowsiness; tired feeling; dry mouth; sore throat, cough; nausea, constipation; or headache.

edit Cost

Claritin costs about $0.42 per tablet, or $12.50 for a pack of 30 tablets on Amazon. Zyrtec pricing is comparable at $22.50 for a pack of 70 on The per tablet pricing of $0.32 is 25% cheaper than Claritin but part of it could be a volume discount because its a bigger pack.

edit References

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