Zyrtec D vs Claritin D

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For patients suffering from allergies or the common cold, certain drugs that mitigate symptoms related to histamine release can make a significant difference in comfort and recovery. Zyrtec D and Claritin D are two such medications often recommended for these conditions. They each function as antihistamines but also contain a decongestant (pseudoephedrine) to help relieve congestion. Zyrtec D is recognized as a second-generation antihistamine known specifically as cetirizine, which may be more likely to induce drowsiness compared to other options. On the other hand, Claritin D contains loratadine - another second-generation antihistamine - that is less sedating than cetirizine but might not control allergy symptoms as effectively for every individual. The choice between these two will primarily depend on balancing symptom relief against potential side effects.

What is Zyrtec D?

Cetirizine (the generic name for Zyrtec D) is a second-generation antihistamine, specifically designed to reduce the common symptoms of allergies such as hay fever without causing drowsiness. It was first approved by the FDA in 1995. Zyrtec D works by blocking histamine receptors in your body, effectively "trapping" histamines and preventing them from producing their usual effects. This results in relief from allergy symptoms like runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat.

On the other hand, Loratadine (the generic name for Claritin D) also belongs to this class of drugs but has some structural differences that cause its effects to be slightly different than those of Cetirizine. While both medications are effective at treating allergic rhinitis and hives, studies suggest that Cetirizine might be more potent than Loratadine with faster onset action although they share similar side effects profile which includes dry mouth and occasional drowsiness.

What conditions is Zyrtec D approved to treat?

Zyrtec D is approved for the treatment of various allergic symptoms, including:

  • Nasal congestion and sinus pressure
  • Runny nose
  • Itchy, watery eyes
  • Sneezing

Claritin D, on the other hand, is also used to treat:

  • Seasonal allergies
  • Perennial or year-round allergies
  • Sinusitis with congestion

Both medications are combination drugs that contain an antihistamine and a decongestant.

How does Zyrtec D help with these illnesses?

Zyrtec D helps to manage allergy symptoms by blocking the action of histamine, a chemical in the body that is released during an allergic reaction. It does this by acting as an antagonist at the histamine H1 receptor, preventing histamine from binding and exerting its effect. Histamine is a compound involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Zyrtec D also contains pseudoephedrine which acts on alpha-adrenergic receptors leading to vasoconstriction and reduction of swelling or inflammation often seen with allergies. In people with allergies, exposure to allergens such as pollen can lead to release of histamines resulting in symptoms like sneezing, itching, runny nose or watery eyes. By blocking histamines and reducing inflammation through vasoconstriction caused by pseudoephedrine , Zyrtec D can limit these negative effects of allergies helping individuals manage their condition effectively.

What is Claritin D?

Claritin-D is a brand name for loratadine combined with the decongestant pseudoephedrine. Loratadine belongs to the class of medications known as antihistamines and works by blocking histamine, a substance in your body that causes allergic symptoms. Pseudoephedrine acts on alpha-adrenergic receptors in the walls of larger air passages and blood vessels, causing them to constrict; this reduces nasal congestion by limiting blood flow back into the nasal tissues which are swollen due to inflamed blood vessels during an allergic reaction. Claritin-D was first approved by the FDA in 2002 and is available over-the-counter or behind pharmacy counters depending on local regulations.

As it does not act on serotonin, its side-effects profile differs from those drugs that do affect serotonin levels — it doesn't lead to sedation nor does it cause weight gain or sexual dysfunction (common side effects of SSRIs). The combination of antihistamine and decongestant can be beneficial for treating allergy symptoms such as runny nose, sneezing, itchy or watery eyes, hives, skin rash, itching and other symptoms of allergies and hay fever.

What conditions is Claritin D approved to treat?

Claritin D is approved for the treatment of:

  • Seasonal allergic rhinitis, also known as hay fever
  • Chronic idiopathic urticaria, more commonly referred to as hives The 'D' in Claritin D refers to the decongestant pseudoephedrine it contains which works alongside loratadine (an antihistamine) to alleviate congestion symptoms associated with these conditions.

How does Claritin D help with these illnesses?

Pseudoephedrine is a decongestant which reduces the swelling of the nasal passages, making it easier to breathe. It's heavily used in allergy medications and plays roles in many processes within the body, affecting congestion relief and sinus pressure alleviation. Claritin D works by combining loratadine, an antihistamine that reduces allergic responses, with pseudoephedrine to combat both allergies and congestion simultaneously. Its action on histamine receptors may also contribute to its effectiveness as an allergy medication. Unlike Zyrtec D, Claritin D does not cause drowsiness in most patients due to its specific formulation. Therefore, it is often recommended for those who do not respond well or have adverse effects such as sedation from other typical over-the-counter allergy medicines like Zyrtec D.

How effective are both Zyrtec D and Claritin D?

Both cetirizine (Zyrtec D) and loratadine (Claritin D) have established histories of successfully treating patients with allergy symptoms, and they were both approved by the FDA in the mid-1990s. Since they act on different histamine receptors, they may be prescribed under different circumstances. The effectiveness of cetirizine and loratadine in alleviating allergy symptoms was directly studied in a double-blind clinical trial; the two drugs demonstrated similar efficacy in managing symptoms such as sneezing, runny nose, itchy or watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.

A 2001 meta-analysis reported that cetirizine is effective from the first dose at relieving rhinitis symptoms and does not cause significant sedative effects compared to placebo. Moreover, this study reports that cetirizine has become one of the most widely used antihistamines globally due to its fast onset of action within an hour after oral administration.

On the other hand, a 2016 review indicated that loratadine seems to be more effective than placebo at reducing allergic rhinitis symptoms without causing drowsiness. Loratadine is typically considered as a first-line treatment option for allergies because it provides all-day relief from multiple allergy symptoms while causing minimal side effects. Nonetheless, research using loratidin alone indicates data confirming its efficacy as less robust than that for cetirizine. This might be due to individual response variations among patients experiencing different types of allergies.

abstract image of a researcher studying a bottle of drug.

At what dose is Zyrtec D typically prescribed?

Oral dosages of Zyrtec D and Claritin D vary depending on the severity of symptoms. For adults and children 12 years and over, both medications can be taken once daily: one tablet of Zyrtec D every 24 hours, or one tablet of Claritin D every 24 hours. Children under 12 years should consult a doctor before use. The dosage may need to be adjusted if there is no relief from symptoms after a few days. Nevertheless, exceeding the recommended dose could lead to severe health risks; hence following the prescribed dosage is crucial in all cases.

At what dose is Claritin D typically prescribed?

Claritin D treatment typically begins with a single tablet (60 mg pseudoephedrine sulfate and 10 mg loratadine) taken orally every 12 hours, not exceeding two tablets in a 24-hour period. For adults who have difficulty swallowing pills, there is also an option to take the medication in liquid form. The dose can be increased to two tablets per day if symptoms do not improve after several days. It's important to note that exceeding the recommended dosage may cause adverse effects such as drowsiness or insomnia. Always consult your healthcare provider prior to adjusting any medication dosages.

What are the most common side effects for Zyrtec D?

Common side effects that may be experienced when taking Zyrtec D include:

  • Dry mouth
  • Dizziness
  • Nervousness
  • Insomnia (difficulty sleeping)
  • Somnolence (sleepiness/drowsiness)
  • Fatigue (general weakness and tiredness)
  • Headache
  • Throat irritation
  • Sinusitis (inflammation of the sinus cavities in the head)

On the other hand, Claritin D users could experience:

  • Dry mouth
  • Sleeplessness or insomnia
  • Headache
  • Feeling nervous or restless
  • Blurred vision
  • Skin rash

Remember, it's essential to report any unusual symptoms you encounter while on these medications and consult with your healthcare provider.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Zyrtec D?

Although Zyrtec D and Claritin D are both effective in managing the symptoms of allergies, they do have potential side effects that you should be aware of. These may include:

  • Abnormal thoughts or behavior, such as hallucinations or paranoia
  • Signs of an allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing
  • Blurred vision or difficulty focusing; seeing halos around lights
  • Fast/irregular/pounding heartbeat; palpitations in your chest; shortness of breath, feeling like you might faint
  • Low potassium levels - muscle weakness/cramps/spasms, irregular heart rhythm
  • Serious nervous system reaction – restlessness/excitement/nervousness/anxiety/sleep problems (insomnia)

Remember to contact your doctor immediately if any worrying symptoms occur while using these medications.

What are the most common side effects for Claritin D?

Claritin D, an antihistamine and decongestant combination, can result in several side effects such as:

  • Dry mouth or throat
  • Blurred vision
  • Feeling nervous or restless
  • Sleep problems (insomnia)
  • Nausea, stomach upset
  • Fast heartbeat
  • Headache, dizziness These symptoms are generally mild and manageable. However, if they persist or worsen over time, it is advisable to contact your healthcare provider promptly. Always remember that taking the medication exactly as prescribed by your doctor can minimize potential side effects.

Are there any potential serious side effects for Claritin D?

While Claritin D is generally well-tolerated, some individuals may experience serious side effects. These could include:

  • Symptoms of a severe allergic reaction like hives; difficulty breathing or swallowing; swelling of the face, lips, tongue or throat
  • Rapid and irregular heartbeat
  • A feeling of faintness or lightheadedness
  • Severe dizziness
  • Unusual mood changes such as agitation or confusion
  • Tremors or seizures (convulsions)

If any of these symptoms are experienced after taking Claritin D, it's crucial to seek immediate medical attention.

Contraindications for Zyrtec D and Claritin D?

Both Zyrtec D and Claritin D, along with most other antihistamine medications, may worsen symptoms of sleeplessness in some people. If you notice your insomnia worsening or an increase in restlessness, please seek immediate medical attention.

Neither Zyrtec D nor Claritin D can be taken if you are taking, or have been taking monoamine oxidase (MAO) inhibitors (MAOIs). Always tell your physician which medications you are taking; MAOIs will require a period of about 2 weeks to clear from the system to prevent dangerous interactions with Zyrtec D and Claritin D.

How much do Zyrtec D and Claritin D cost?

For the brand name versions of these drugs:

  • The price for 24 tablets of Zyrtec-D (5-120 mg) averages around $20, which works out to approximately $0.83 per day.
  • The price for 30 tablets of Claritin-D (10-240 mg) is about $25, working out to roughly $0.83 per day.

Considering this, both Zyrtec-D and Claritin-D have a similar cost on a per-day treatment basis. Remember that cost should not be the primary factor in determining which of these medications is right for you.

For the generic versions of Zyrtec-D (cetirizine-pseudoephedrine) and Claritin-D (loratadine-pseudoephedrine), costs are significantly lower:

  • Cetirizine-Pseudoephedrine can be found in packs ranging from 15 to 60 tablets with approximate costs starting at as low as $0.50/day if you buy larger packs upfront.

  • Loratadine-Pseudoephedrine also comes in various sized packs with prices beginning from about $0.45/day depending on pack size.

These medications may offer relief from allergy symptoms but always consult your healthcare provider before starting any new medication regimen.

Popularity of Zyrtec D and Claritin D

Cetirizine, known by the brand name Zyrtec D, was estimated to have been sold to about 6.2 million people in the US in 2020. Cetirizine accounted for just over 15% of antihistamine purchases in the US. However, it appears to be one of the most common "second-generation" antihistamines (known for less drowsiness compared to first-generation). The prevalence of cetirizine sales has generally been increasing since its introduction.

Loratadine-D, including brand versions such as Claritin D, was purchased by approximately 5 million people in the USA in 2020. In the US market share, loratadine accounts for roughly around 13% of second-generation antihistamine purchases and is one of top choices among consumers seeking relief from allergy symptoms without drowsiness side effect. The prevalence rate for loratadine has remained approximately steady over the last decade.


Both Zyrtec D (cetirizine and pseudoephedrine) and Claritin D (loratadine and pseudoephedrine) have long-standing records of usage in patients with allergies, particularly those experiencing nasal congestion. They are backed by numerous clinical studies indicating that they are more effective than placebo treatments. Both contain an antihistamine combined with a decongestant, but this combination should be used under careful consideration as there can be contraindications for certain individuals such as those with uncontrolled high blood pressure or heart disease.

Due to their different active ingredients, Zyrtec D may provide relief from symptoms faster than Claritin D, while the latter tends to last longer. Both medications may require an adjustment period, meaning effects might not be noticeable right away.

Both drugs are available in generic form which represents significant cost savings especially for patients who must pay out of pocket.

The side effect profile is similar between the two drugs; both being generally well-tolerated but Zyrtec D may cause more drowsiness compared to Claritin D. For both drugs, if allergy symptoms persist or worsen after use or any adverse reaction is experienced like rapid heartbeat or nervousness, professional medical help should be sought immediately.