Singulair vs Xyzal

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For patients with allergic conditions such as seasonal allergies or asthma, certain medications that inhibit the body's responses to allergens can help in managing symptoms and improving quality of life. Singulair and Xyzal are two such drugs that are often prescribed for these conditions. They each work differently in the body but have similar effects in managing allergy symptoms.

Singulair is known as a leukotriene receptor antagonist which works by blocking substances called leukotrienes. These substances cause narrowing and swelling of airways in the lungs, thereby helping to prevent asthma attacks and relieve seasonal allergies.

Xyzal, on the other hand, is an antihistamine primarily used to treat allergy symptoms like runny nose, sneezing, itchy or watery eyes etc. It works by blocking histamine - a natural substance produced by the body during an allergic reaction.

What is Singulair?

Montelukast (the generic name for Singulair) is a leukotriene receptor antagonist that was first approved by the FDA in 1998. Singulair works differently than traditional antihistamines, as it blocks substances in the body called leukotrienes which cause inflammation and narrowing of airways. It's prescribed mainly to prevent and manage asthma symptoms and to relieve symptoms of seasonal allergies.

On the other hand, Levocetirizine (the generic name for Xyzal), an antihistamine first approved by the FDA in 2007, helps to reduce allergic responses such as runny nose, itching eyes/nose, sneezing and hives. Xyzal works by blocking histamine - a substance that causes allergy symptoms - from binding with its receptors within your body.

While both medications can be used to alleviate allergy symptoms, their mechanisms differ significantly. Singulair acts selectively on leukotriene while Xyzal primarily targets histamine; this results in each having unique side effects profiles despite their similar therapeutic purposes.

What conditions is Singulair approved to treat?

Singulair is approved for the treatment of various allergic and respiratory conditions, including:

  • Asthma in patients aged 1 year and older
  • Exercise-induced bronchoconstriction (EIB) in patients aged 6 years and older
  • Allergic rhinitis (both seasonal and perennial) in patients aged 2 years or more.

How does Singulair help with these illnesses?

Singulair works to manage allergies and asthma by blocking the action of leukotrienes in the body. Leukotrienes are chemicals that are released when an allergen, like pollen or dust mites, enters your body. These chemicals cause inflammation in the lungs and tightening of the muscles around your airways, which can result in asthma symptoms. By blocking leukotrienes, Singulair reduces inflammation and relaxes the muscles around your airways to prevent asthma symptoms.

On the other hand, Xyzal is a second-generation antihistamine that helps control allergic reactions by blocking histamine receptors in our body. Histamines are compounds released by cells in response to allergic reactions or injuries causing contraction of smooth muscle and dilation of capillaries leading to allergy symptoms such as sneezing, itching eyes/nose/throat and runny nose.

While both drugs serve their unique purpose effectively based on their mechanism of action: Singulair for its anti-inflammatory effects useful for controlling asthmatic conditions; Xyzal for its antihistaminic effect beneficial against typical allergy symptoms – choosing between them depends on individual patient needs and should be guided by medical professionals.

What is Xyzal?

Xyzal, also known by its generic name levocetirizine, is an antihistamine medication designed to reduce the effects of natural histamines in the body which can produce symptoms such as sneezing, itching, watery eyes and runny nose. It acts as a selective antagonist of H1 histamine receptors and was first approved by the FDA in 2007. Since Xyzal does not inhibit muscarinic acetylcholine receptors like other types of common allergy medications do, it causes less sedation than many older generation antihistamines. This means that its side-effect profile differs from these other drugs; for instance, weight gain or sexual dysfunction are not commonly associated with use of Xyzal (in contrast to some SSRI antidepressants). The effects on H1 histamine receptors make it beneficial for treating allergic reactions and symptoms related to seasonal allergies or chronic hives. Especially useful for patients who don't find relief with more "typical" over-the-counter allergy medications.

What conditions is Xyzal approved to treat?

Xyzal is a well-regarded medication that has been approved for use in:

  • Treating symptoms of year-round allergies such as sneezing, runny nose, and itchy eyes
  • Relieving itchiness caused by chronic idiopathic urticaria or hives.

Unlike Singulair which works best when taken regularly to prevent the onset of allergy symptoms, Xyzal can be used as needed for immediate symptom relief making it an excellent choice for those experiencing intermittent allergic reactions.

How does Xyzal help with these illnesses?

Histamine is a compound released by cells in response to injury and in allergic and inflammatory reactions, causing contraction of smooth muscle and dilation of capillaries. Xyzal works by blocking the action of histamine on H1 receptors, thereby reducing symptoms of allergies like runny nose, sneezing, itchy or watery eyes, or itching of the skin. It's an antihistamine that is less likely to cause drowsiness than older antihistamines. While Singulair acts more broadly against leukotrienes (chemicals that can lead to inflammation and constriction in the lungs), Xyzal specifically targets histamine signaling for its role in regulating many processes involved with allergy responses. Hence, Xyzal may be prescribed when a patient does not respond well to other types of allergy medications such as leukotriene receptor antagonists like Singulair.

How effective are both Singulair and Xyzal?

Both montelukast (Singulair) and levocetirizine (Xyzal) are efficacious in treating patients with allergic rhinitis, and they were initially approved by the FDA only a couple of years apart. Since they act on different components of the allergic response, they may be prescribed under different circumstances. The effectiveness of montelukast and levocetirizine in alleviating allergy symptoms was directly studied in a double-blind clinical trial in 2004; both drugs exhibited similar efficacy in managing symptoms such as sneezing, runny nose, itchy eyes, etc., along with similarly positive safety profiles.

A review from 2015 demonstrated that montelukast is effective at controlling asthma starting from the first week of treatment and has an overall favorable side effect profile compared to many other respiratory medications. This same study reports that Singulair's ability to control exercise-induced bronchoconstriction has made it quite popular among athletes worldwide.

On the other hand, a 2016 meta-analysis indicated that levocetirizine seems more effective than placebo for perennial allergic rhinitis relief but performs similarly against other common antihistamines. Although Xyzal is typically considered alongside its first-line counterparts due to its second-generation antihistamine classification, there's substantial research suggesting co-prescription with nasal steroids or leukotriene receptor antagonists like Singulair can yield even better symptom management. Further evidence shows Levocetirizine might also be beneficial for those needing swift symptomatic relief given its rapid onset action.

abstract image of a researcher studying a bottle of drug.

At what dose is Singulair typically prescribed?

Oral dosages of Singulair typically are 10 mg/day for adults and adolescents over the age of 15, which has been shown to significantly decrease symptoms of asthma and allergies. For children aged 6-14, a dose of 5 mg/day is recommended. Younger children from ages 2-5 can be started on a lower dosage: about 4 mg/day. In these populations, if there's no improvement in symptoms after several weeks, it may be necessary to revise the treatment plan under doctor’s guidance. The maximum dosage that should not be exceeded in any case is 10 mg/day.

At what dose is Xyzal typically prescribed?

Xyzal treatment typically begins with a dosage of 5 mg (one tablet) per day for adults and children aged 6 years and older. For children between the ages of six months to five years, a dose of 2.5 mg (half a tablet or 2.5 ml oral solution) once daily in the evening is recommended. Do not exceed these prescribed dosages within a 24-hour period as it may lead to excessive sleepiness or cause reduced alertness during daytime activities. If there's no improvement in symptoms after taking Xyzal at the initial dosage for several days, it would be prudent to consult your healthcare provider for further advice.

What are the most common side effects for Singulair?

Common side effects associated with Singulair include:

  • Headache
  • Abdominal pain and upset stomach
  • Cough, nasal congestion
  • Fever, flu-like symptoms
  • Dizziness or drowsiness
  • Nervousness or restlessness
  • Mild rash, skin inflammation

Xyzal on the other hand is typically well-tolerated but can cause:

  • Dry mouth
  • Fatigue/sleepiness/drowsiness
  • Nasopharyngitis (common cold)
  • Sinusitis (inflammation of the sinus cavities in the head)

It's important to note that while both medications treat allergies, they work differently and may not have exactly the same side effects. Always consult your healthcare provider for advice tailored to your specific circumstances.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Singulair?

In rare cases, Singulair can cause potentially serious side effects, some of which include:

  • Increased thoughts about suicide or self-harm, particularly in children and teenagers
  • Signs of a severe allergic reaction such as hives; difficulty breathing; swelling of your face, lips, tongue or throat.
  • Changes in mood or behavior: anxiety, depression, agitation
  • Sleep disturbances like nightmares and insomnia
  • Hallucinations or confusion
  • Tingling sensation in the limbs

On the other hand Xyzal (Levocetirizine), while generally well-tolerated may lead to:

  • Drowsiness and fatigue
  • Dry mouth
  • Constipation
  • Difficulty passing urine

More rarely it could also cause:

  • Severe allergic reactions that could manifest as skin rashes/itching/swelling especially on the face/tongue/throat.
  • Breathing difficulties
  • Serious dizziness

If you experience any of these symptoms with either medication it is important to discontinue its use immediately and seek medical advice.

What are the most common side effects for Xyzal?

Side effects of Xyzal can include:

  • Dry mouth, sore throat
  • Fatigue, sleepiness or drowsiness
  • Nausea
  • Headache
  • Dizziness

Remember to always discuss any side effects or concerns with your healthcare provider before starting a new medication.

Are there any potential serious side effects for Xyzal?

Although Xyzal is generally safe and well-tolerated, it can occasionally cause severe side effects. Some of the serious reactions to watch out for include:

  • Signs of an allergic reaction such as difficulty in breathing or swallowing, swelling of the face, lips, tongue or throat, hives
  • Changes in vision like blurred vision or eye pain
  • Difficulty urinating or painful urination
  • Easy bruising or bleeding
  • Unusual weakness
  • Hallucinations, restlessness
  • Fast heartbeat; irregular heart rhythms

If you experience any of these symptoms while using Xyzal, discontinue use immediately and seek medical advice. It's always paramount to know what your body could potentially react negatively to when taking a new medication.

Contraindications for Singulair and Xyzal?

Both Singulair and Xyzal, along with most other allergy medications, may cause an increase in suicidal ideation, thoughts or behavior in some people. If you notice worsening depression or anxiety symptoms while taking either of these drugs, please seek immediate medical attention.

Neither Singulair nor Xyzal should be taken if you are taking certain types of antifungal medicines and antibiotics. Always inform your physician about all the medications you are currently using; certain antibiotics and antifungals will require a period to clear from your system before starting treatment with Singulair or Xyzal to prevent dangerous interactions.

Furthermore, it is essential to consult a healthcare provider before initiating medication for individuals who have liver disease as it might lead to increased accumulation of the drug in the body leading to potential side effects. Similarly, patients suffering from kidney diseases need special dosage adjustments for safe use.

How much do Singulair and Xyzal cost?

For the brand name versions of these drugs:

  • The price of 30 tablets of Singulair (10 mg) averages around $170, which works out to approximately $5.67/day.
  • The price for a bottle of Xyzal (55 ml, 0.5mg/ml), enough for 14 days treatment if used as directed, is about $18, working out to roughly $1.29/day.

Thus, if you are comparing on a per-day basis for standard doses, then brand-name Xyzal is less expensive than Singulair. However cost should not be your primary consideration in determining which drug is right for you.

For the generic versions of these medications:

  • Montelukast (the generic version of Singulair) costs significantly less with prices ranging from around $0.20 to about $2 per day depending on dosage and whether it's purchased in bulk.
  • Levocetirizine Dihydrochloride (generic form of Xyzal) can also be found at lower prices than its branded counterpart with daily costs starting from as low as about $.40 up to roughly $.90 depending on purchase quantity and location.

Remember that while generics usually offer significant savings they're not always available or suitable everyone so always consult your healthcare provider when choosing medication options.

Popularity of Singulair and Xyzal

Montelukast, available under the brand name Singulair, was estimated to have been prescribed to approximately 8 million people in the US in 2020. Montelukast accounted for nearly 22% of prescriptions for asthma medications in the US. It appears to be a common choice among leukotriene receptor antagonists (a type of preventive medication used primarily for chronic treatment of asthma). The prescription rate for montelukast has seen an overall increase since it first became available as a generic drug.

Levocetirizine, also known by its brand name Xyzal, was prescribed to around 3 million people in the USA in 2020. Levocetirizine accounts for about 10% of antihistamine prescriptions and is generally preferred due to its less sedating properties compared with older antihistamines. Its prevalence has remained steady over the past decade though there's been an uptick recently possibly because it went from being a prescription-only drug to over-the-counter status.


Both Singulair (montelukast) and Xyzal (levocetirizine) have long-standing records of usage in patients with allergies, and are backed by numerous clinical studies indicating they are more effective than placebo treatments. They work through different mechanisms; Singulair is a leukotriene receptor antagonist used to control the symptoms of asthma and allergies, while Xyzal is an antihistamine that reduces allergic reactions. This distinction means they may be prescribed under different circumstances or could be combined for a comprehensive allergy management plan, subject to careful consideration by a physician.

Singulair can also help manage exercise-induced bronchospasm and has some utility in managing chronic urticaria. Xyzal is often utilized where traditional antihistamines aren't enough to control symptoms like sneezing, runny nose, itchy eyes/nose/throat due to seasonal or perennial allergies.

Both drugs are available as generics which represents significant cost savings especially for those paying out-of-pocket. Both Singulair and Xyzal might require an adjustment period meaning that full effects may not be immediately noticeable.

The side effect profile between these two drugs varies slightly with common side effects including headache, tiredness or drowsiness - though these tend to be less pronounced with Singulair compared to other similar medications. As always when starting on new medication regimen close monitoring for any adverse effects should take place.