Comparing Desloratadine and Levocetirizine: Antihistamines for Allergy Treatment

Desloratadine and Levocetirizine, both belonging to the second-generation antihistamines, are frequently prescribed for managing allergies. As H1 receptor antagonists, their shared function involves inhibiting the activity of histamine in the body.

While these medications exhibit similar indications and mechanisms of action, subtle variations in their effectiveness can be observed among individual patients. Notably, a study has suggested that Levocetirizine might be a preferred option for allergic rhinitis due to its quicker onset of action and more consistent effects than desloratadine.

In this article, we will delve into the distinctions between these antihistamines, examining their mechanisms of action, efficacy in allergy treatment, potential side effects, recommended dosages, and cost implications.

1. Mechanism of Action

When allergies strike, histamine is released, triggering irritating symptoms. Desloratadine and levocetirizine block histamine receptors, disarming allergies. But how do their approaches compare? Let’s break it down below.

Desloratadine

Desloratadine belongs to a class of medications called antihistamines. By inhibiting histamine release, Desloratadine helps relieve symptoms such as:

• Sneezing
• Runny nose
• Itching
• Red, itchy eyes associated with hay fever
• Urticaria (hives)

Levocetirizine

Levocetirizine also belongs to the class of antihistamines. It works similarly and help alleviate symptoms like:

• Runny nose
• Sneezing
• Itching
• Tearing of the eyes caused by hay fever, seasonal allergies, and other allergens

Additionally, it effectively treats hives symptoms, including itching and rash.

2. Efficacy

Allergies disrupt daily life with irritating symptoms. Do desloratadine and levocetirizine eliminate symptoms with equal effectiveness?

Desloratadine

Desloratadine is noted for its potent anti-allergic effects, inhibiting cell adhesion molecules, inflammatory mediators, and cytokines. In addition to these effects, clinical trials consistently demonstrate its significant control over nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR), ultimately contributing to an enhanced overall quality of life. Furthermore, its non-sedating nature is underscored by its inability to cross the blood-brain barrier, ensuring no sedation.

Moreover, studies affirm that desloratadine maintains a favorable safety profile at nine times the recommended dose. This, combined with its efficacy in reducing symptoms in both SAR and chronic idiopathic urticaria, further supports its role in improving health-related quality of life.

In reviews, desloratadine is consistently characterized as a non-sedating histamine H1-receptor antagonist with a well-established safety and efficacy profile, particularly in allergic inflammatory disorders.

Research focused on perennial allergic rhinitis over a 4-week period adds to the evidence, showcasing desloratadine's ability to safely and substantially reduce symptoms, including nasal congestion.

Additionally, postmarketing surveillance studies involving a substantial cohort of over 77,000 subjects validate desloratadine's real-world safety and efficacy in managing seasonal allergic rhinitis and chronic idiopathic urticaria. The drug's well-tolerated profile is further emphasized, demonstrating significant reductions in various allergy symptoms and minimizing disruptions in sleep and daily activities.

Levocetirizine

Levocetirizine, as revealed by multiple studies, proves to be a highly effective treatment for allergic diseases, particularly allergic rhinitis and chronic idiopathic urticaria. Clinical trials consistently demonstrate its efficacy, showcasing a rapid onset of action, high bioavailability, and a notable affinity for the H1 receptor.

In the context of seasonal allergic rhinitis, placebo-controlled trials establish that all three dosage levels of levocetirizine (2.5, 5, and 10 mg) significantly outperform placebo in reducing the mean Total Four-Symptom Score (T4SS) over two weeks. The T4SS, derived from individual symptom scores excluding nasal congestion, gauges the severity of sneezing, rhinorrhea, nasal pruritus, and ocular pruritus.

Individual symptom severity scores for sneezing, rhinorrhea, itchy nose, and itchy eyes also exhibit significant reductions for all doses of levocetirizine. The 5 mg once-daily dosage emerges as the optimal choice, demonstrating an apparent benefit/risk ratio in treating seasonal allergic rhinitis.

Comprehensive reviews of pharmacological profiles and clinical trials affirm that levocetirizine is consistently efficacious and generally well-tolerated across diverse populations, including adults and children aged 6-12. It effectively relieves symptoms and enhances the quality of life, as evidenced by improvements in work productivity and daily activities.

3. Dosage

The right dosage delivers optimal relief. How should desloratadine and levocetirizine be dosed?

Desloratadine

For adults, the usual dosage is 5 mg orally once a day. In cases of intermittent allergic rhinitis, treatment may be discontinued after symptom resolution and reinitiated upon reappearance. Continuous treatment may be considered during periods of allergen exposure for persistent allergic rhinitis.

Pediatric dosages are determined by age:

• 1-5 years: 1.25 mg once daily
• 6-11 years: 2.5 mg once daily
• 12 years and older: Same as the adult dose

In cases of moderate to severe kidney or liver impairment, the initial recommended dose is 5 mg every other day.

Desloratadine can be taken with or without food. It is important to note that patients with a medical or family history of seizure disorders, as well as those who are slow or poor metabolizers of desloratadine, may have an increased risk of adverse effects. Monitoring for signs and symptoms of hypersensitivity reactions is crucial.

Levocetirizine

The usual dosage for adults with allergic rhinitis or urticaria is 5 mg once daily in the evening. Some patients may find sufficient relief with a lower dose of 2.5 mg once a day.

For pediatric patients, the dosage is adjusted based on age. Children aged 6 months to 5 years are typically prescribed 1.25 mg once daily, while those aged 6 to 11 receive 2.5 mg once daily in the evening. Children 12 years and older are prescribed the same dose as adults, 5 mg once daily.

The dosage is adjusted according to creatinine clearance (CrCl) levels in patients with kidney impairment. Levocetirizine is contraindicated in pediatric patients aged 6 months to 11 years with impaired kidney function. For adults and children 12 years or older, the dosage is adjusted as follows:

• Mild kidney dysfunction (CrCl 50 to 80 mL/min): 2.5 mg orally once a day
• Moderate kidney dysfunction (CrCl 30 to 50 mL/min): 2.5 mg orally once every other day
• Severe kidney dysfunction (CrCl 10 to 30 mL/min): 2.5 mg orally twice a week (administered once every 3 to 4 days)
• End-stage kidney disease (CrCl less than 10 mL/min): Contraindicated

The medication can be taken with or without food, and the tablets are scored, allowing them to be broken if necessary.

4. Side Effects

Antihistamines can cause side effects like drowsiness. What should you know about the safety profiles of desloratadine and levocetirizine?

Desloratadine

Common Side Effects

• Headache
• Nausea
• Diarrhea
• Dizziness
• Sore throat
• Dry mouth
• Muscle pain
• Extreme tiredness
• Sleepiness
• Painful menstruation

Serious Side Effects

• Rash
• Itching
• Hives
• Difficulty swallowing or breathing
• Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs

Levocetirizine

Common Side Effects

• Sleepiness
• Tiredness
• Weakness
• Sore throat
• Dry mouth
• Fever
• Cough
• Nosebleed

Serious Side Effects

• Hives
• Rash
• Itching
• Swelling of the arms, hands, feet, ankles, or lower legs

Other Considerations

• Levocetirizine may cause drowsiness; avoid driving or operating machinery.
• Alcohol can add to the drowsiness caused by this medication; discuss the safe use of alcoholic beverages with your doctor.

5. Cost and Availability

Affordability impacts medication access. How do the costs of desloratadine and levocetirizine compare?

Desloratadine

Desloratadine, marketed under the brand Clarinex, is available in oral tablet form with a strength of 5 mg. The supply of 90 tablets is approximately $127, depending on the pharmacy. These prices are for cash-paying customers and may not be valid with insurance plans. A disintegrating tablet form is also available at around $158.04 for 30 tablets.

While no specific manufacturer promotions or patient assistance programs are listed for desloratadine, there is a Drugs.com discount card that can provide savings of up to 80% or more of the prescription cost. This card is accepted at major pharmacy chains across the U.S.

Levocetirizine

Levocetirizine, branded as Xyzal, is offered in oral tablet form with a strength of 5 mg. The cost for a supply of 30 tablets is approximately $13, depending on the pharmacy. Similarly to desloratadine, these prices are for cash-paying customers and may not be valid with insurance plans. An oral solution is also available at around $33.05 for 118 milliliters.

Similar to desloratadine, no specific manufacturer promotions or patient assistance programs are listed for levocetirizine. However, a Drugs.com discount card offers potential savings of up to 80% or more.

Wrap Up

Levocetirizine may have a faster onset of action and more consistent effects than desloratadine for allergic rhinitis. Levocetirizine also seems to cause more drowsiness.

In terms of dosage, desloratadine has a once-daily dosage for adults, while levocetirizine dosage varies by age.

For side effects, desloratadine is less likely to cause drowsiness than levocetirizine. Regarding cost, both medications are similarly priced for a 30-day supply.

Overall, while both medications are effective antihistamines, levocetirizine may provide faster relief for some patients with allergic rhinitis, but desloratadine is less likely to cause drowsiness as a side effect.

Which is better for allergies, cetirizine or levocetirizine?

Levocetirizine is a potent antihistamine, scoring an average rating of 5.6 out of 10 from 341 reviews on Drugs.com. 44% reported positive effects, while 40% reported negative effects. Conversely, Cetirizine scored 5.8 out of 10 from 289 reviews, with 46% reporting positive effects and 36% reporting negative effects.

Is levocetirizine a strong antihistamine?

Yes, levocetirizine is a strong antihistamine, demonstrated by its ability to effectively inhibit cutaneous histamine-induced itching and the wheal and flare reaction.

What should I avoid while taking levocetirizine?

To minimize the risk of heightened side effects like dizziness, poor concentration, drowsiness, unusual dreams, and difficulty sleeping, steer clear of alcohol and other medications affecting the central nervous system when using levocetirizine.

What's the brand name for levocetirizine?

Levocetirizine is sold under the brand name Xyzal. This second-generation antihistamine is effectively used to treat allergic rhinitis (hay fever) and long-term hives with an unclear cause. Notably, Xyzal is known for being less sedating compared to older antihistamines.

What is loratadine, and how does it differ from desloratadine?

Loratadine is an antihistamine used for allergies, while desloratadine is its active metabolite. Desloratadine is considered more potent and longer-lasting.

Can loratadine be used for treating allergies?

Yes, loratadine is an allergy medicine commonly used to relieve symptoms such as sneezing, itching, and runny nose.

What are the uses of desloratadine?

Desloratadine is primarily used to treat symptoms of allergic conditions, including hay fever and hives. It provides relief from itching, sneezing, and other allergic reactions.

Are there any side effects associated with levocetirizine?

Levocetirizine, like any medication, may have side effects. Common side effects include drowsiness, fatigue, and dry mouth. Consult your healthcare provider if you experience any concerning side effects.

What are the uses of levocetirizine?

Levocetirizine is an antihistamine used to relieve symptoms of allergic conditions, such as hay fever, allergic rhinitis, and chronic idiopathic urticaria.