Allegra vs Claritin

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For individuals with allergic reactions, certain drugs that inhibit the release of histamine, a compound in the body responsible for allergy symptoms, can help manage these discomforts. Allegra and Claritin are two such medications often recommended for allergies. They each impact the histamine production differently but both effectively alleviate allergy symptoms. Allegra (Fexofenadine) is an antihistamine that works by blocking H1 receptors to reduce symptomatic inflammation and itchiness associated with allergies without causing drowsiness. On the other hand, Claritin (Loratadine) also acts as an antihistamine by preventing H1 receptor activation but is metabolized differently in the body, potentially making it less effective for some individuals depending on their metabolic response to medication.

What is Allegra?

Fexofenadine (the generic name for Allegra) was a significant advancement in the second generation of antihistamine drugs, which were developed to cause fewer side effects than their first-generation counterparts. Fexofenadine was first approved by the FDA in 1996. Allegra works by preventing histamine from binding to its receptors, thereby stopping the allergic reaction and its symptoms like runny nose or itchy eyes. It is prescribed for relieving both indoor and outdoor allergy symptoms.

Loratadine (the generic name for Claritin), another second-generation antihistamine approved in 1993, also serves a similar purpose but has slight differences. Claritin takes longer to react within your body system compared to Allegra but lasts longer providing relief up to 24 hours.

Both medications are considered non-sedating, meaning they shouldn't make you drowsy or slow down your reactions; however, some people may have different experiences so it's always best to see how these medications affect you personally.

What conditions is Allegra approved to treat?

Allegra is used to manage the symptoms of several conditions:

  • Seasonal allergic rhinitis (SAR), also known as hay fever
  • Chronic idiopathic urticaria (CIU), commonly referred to as hives caused by an unknown source
  • Perennial allergic rhinitis (PAR), a year-round condition characterized by nasal congestion, runny nose, and itchy or watery eyes.

How does Allegra help with these illnesses?

Allegra, also known as fexofenadine, helps to manage allergies by blocking the effects of histamine in the body. Histamine is a chemical that's released when your immune system reacts to foreign substances known as allergens. It does this by attaching itself to receptors on cells in your body and triggering an allergic response such as sneezing, itching or hives. Allegra acts by binding to these same receptors but instead of activating them, it prevents histamine from doing so - thus reducing or preventing allergy symptoms. Claritin (loratadine) works similarly but unlike Allegra which doesn't cross the blood-brain barrier significantly and is therefore less likely to cause drowsiness; Claritin does have some ability to cross into the brain which may lead to sedation in some individuals. Therefore, choosing between Allegra and Claritin can depend on how a person responds individually with regard their alertness levels while taking either drug for managing their allergies.

What is Claritin?

Claritin is a brand name for loratadine, which is a second-generation antihistamine. This means it works by blocking the release of histamine in the body, thereby reducing symptoms of allergies such as sneezing, itching and runny nose. It also has less tendency to cause sedation compared to first-generation antihistamines because loratadine does not readily cross the blood-brain barrier. Claritin was first approved by the FDA in 1993.

Unlike Allegra (fexofenadine), another second-generation antihistamine, Claritin does not have any significant interaction with grapefruit juice or fruit. This makes it more convenient for many users who enjoy these fruits or their juices without having to worry about possible drug-food interactions that can alter medication effectiveness. Mild side effects such as headache and dry mouth are common but generally tolerable; serious side-effects are rare. The effects on allergic reactions can be beneficial especially in patients who don't respond well to "typical" first-generation antihistamines.

What conditions is Claritin approved to treat?

Claritin, also known as loratadine, is an antihistamine that has been approved by the FDA for the treatment of:

  • Seasonal Allergic Rhinitis (hay fever)
  • Chronic Idiopathic Urticaria (long-term hives or skin rash)

These conditions are characterized by symptoms such as a runny nose, sneezing, itchy or watery eyes - all of which Claritin can effectively alleviate.

How does Claritin help with these illnesses?

Histamine is an organic compound involved in local immune responses and regulating physiological functions in the gut, acting as a neurotransmitter for the brain, spinal cord, and uterus. It also plays a central role in mediating itching sensations caused by allergic reactions. Claritin works by blocking histamine receptors present on cells' surface throughout our body to alleviate symptoms of allergies such as sneezing, runny nose or hives. Unlike Allegra which selectively inhibits peripheral H1-receptors (histamine receptors largely found outside the brain), Claritin can cross blood-brain barrier due to its lipophilic nature causing mild drowsiness though significantly less than first-generation antihistamines. Because it does not specifically target only one type of histamine receptor, it may potentially be more effective for some patients compared to other “typical” second-generation antihistamines like Allegra.

How effective are both Allegra and Claritin?

Both fexofenadine (Allegra) and loratadine (Claritin) have proven efficacy in treating patients with allergic rhinitis, and they were approved by the FDA within a few years of each other. Fexofenadine and Loratadine work as antihistamines but target different histamine receptors, which means they might be prescribed under different circumstances depending on individual patient needs. The effectiveness of Allegra and Claritin in alleviating allergy symptoms was directly studied in several double-blind clinical trials during the 1990s; both drugs showed similar efficacy in managing symptoms such as sneezing, runny nose, itchy or watery eyes.

A review of meta-analysis reports on fexofenadine demonstrated that it is effective in alleviating allergy symptoms from the first dose onward and its side effect profile is favorable over many other antihistamines due to its non-sedating nature. It has become one of the most widely-prescribed antihistamine drugs worldwide. Further research shows optimal symptom relief occurs at doses between 120-180 mg/day.

A 2016 review indicated that loratadine seems to be more effective than placebo in treating allergy symptoms and appears to have comparable efficacy to other common second-generation antihistamines like fexofenadine. Nonetheless, significant research involves loratidine being used alongside decongestant pseudoephedrine so data confirming its standalone efficiency isn't as robust compared to fexofenadine's. But considering individual pharmacology differences, Loratidine may be an optimal treatment for those who did not respond well to other second-generation antihistamines or need a cost-effective alternative since it's available over-the-counter.

abstract image of a researcher studying a bottle of drug.

At what dose is Allegra typically prescribed?

Oral dosages of Allegra, also known as fexofenadine, for adults and children 12 years and older range from 60 mg twice daily or 180 mg once daily. Children between the ages of 6-11 may start on a dose of 30mg twice daily. In either population, dosage can be adjusted based on response to medication. The maximum recommended dose is not to exceed 180 mg in a single day. Similarly, Claritin (loratadine) dosing varies by age: adults and children over six should take one 10mg tablet per day; younger children (2-5 years old) should receive only half that dose - i.e., one chewable 5 mg tablet per day or using liquid syrup form at the same dosage strength. Exceeding these doses within a single day is not typically recommended.

At what dose is Claritin typically prescribed?

Claritin treatment is typically initiated at a dosage of 10 mg/day for adults and children aged 6 years and over. This can be taken once daily, either in the morning or evening as per individual comfort. For younger kids between ages 2-5, the recommended dose is 5mg/day (half tablet). It's crucial to remember that exceeding this daily limit may lead to adverse side effects such as drowsiness or headaches. If there's no significant relief from allergy symptoms after a few days of regular usage, it might be necessary to consult with your healthcare provider for further advice or an alternative medication plan.

What are the most common side effects for Allegra?

Common side effects of Allegra and Claritin include:

  • Drowsiness or sleepiness
  • Headache
  • Dry mouth
  • Nausea and stomach discomfort
  • Diarrhea
  • Muscle aches or back pain
  • Menstrual cramps (in some cases)

Less common but more serious side effects can also occur. If you experience symptoms such as rapid heartbeat, yellowing eyes/skin, dark urine, persistent nausea/vomiting, fatigue, or nervousness after taking either medication, seek immediate medical assistance.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Allegra?

While both Allegra and Claritin are similar in numerous ways, they can each have different side effects. Rare yet serious side effects of Allegra could include:

  • Signs of allergic reaction: hives, difficulty breathing or swallowing, swelling in your face or throat
  • Rapid heartbeat or palpitations
  • Flu-like symptoms: fever, chills, body aches
  • Nervous system reactions - feeling restless, anxious or uneasy; having trouble sleeping

For Claritin these rare but serious side effects may occur:

  • Severe dizziness
  • Difficulty urinating – this might suggest prostate problems
  • An allergic reaction such as rash, itching/swelling (particularly around the face/tongue/throat), severe dizziness and trouble breathing

If any of these symptoms appear after taking either medication it is important to seek immediate medical care.

What are the most common side effects for Claritin?

The following are potential side effects of Claritin:

  • Dry mouth
  • Fatigue and drowsiness
  • Headache, nervousness
  • Sore throat, sinus congestion
  • Sleep problems (insomnia)
  • Stomach upset such as nausea or diarrhea
  • Eye redness or blurred vision
  • Nosebleeds.

It's important to note that everyone is unique and the way one person reacts to a medication may be different from another's experience. Always consult with your healthcare provider for personalized advice on medications.

Are there any potential serious side effects for Claritin?

While Claritin is generally considered safe for most individuals, it's important to be aware of potential adverse effects. Although very rare, some serious side effects that may occur include:

  • Signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
  • Severe dizziness and nervousness
  • Rapid heartbeat or fluctuating heart rate
  • Unusual changes in behavior or mood swings
  • Difficulty concentrating
  • Yellowing eyes/skin which can indicate a severe liver problem
  • Dark urine due to dehydration

If you experience any signs of these serious side effects while taking Claritin, stop its use immediately and seek medical attention right away. Also remember that even OTC medications like Claritin should ideally be taken under the guidance of a healthcare professional.

Contraindications for Allegra and Claritin?

Both Allegra and Claritin, like other antihistamine medications, may cause side effects in some people. If you notice any unusual symptoms such as rapid heartbeat, dizziness or difficulty breathing after taking these drugs, please seek immediate medical help.

Neither Allegra nor Claritin should be taken if you are using ketoconazole or erythromycin; this is because these medications can affect the way your body metabolizes antihistamines leading to potential overexposure. Always tell your physician which medications you are taking; these drugs will require a certain period of time to clear from the system to prevent dangerous interactions with Allegra and Claritin.

Furthermore, both medicines can make you feel drowsy; if this happens avoid driving or operating heavy machinery until you know how these medicines affect you. As always consult with your healthcare provider for advice about individual health concerns.

How much do Allegra and Claritin cost?

For the brand name versions of these drugs:

  • The price for 30 tablets of Allegra (180 mg) averages around $19, which works out to approximately $0.63/day.
  • The price for 30 tablets of Claritin (10 mg) is about $22, working out to roughly $0.73/day.

Thus, if you are taking one tablet per day as recommended for either drug, then brand-name Allegra is less expensive on a per-day treatment basis. However, cost should not be your primary consideration in determining which antihistamine is right for you.

As for generic versions:

  • Fexofenadine (generic Allegra), available in packs starting from 15 up to over-the-counter large quantities like 500 tablets at doses of 180mg each has costs ranging from as low as under a dollar a day up to approximately $2/day depending on quantity bought and source.

  • Loratadine (generic Claritin) can also be found in packs varying from small quantities like 15 capsules all the way up to bulk purchases exceeding several hundred pills with daily cost estimates going from just cents to about a dollar depending again on volume purchased and where you buy it.

Both generics provide significant savings compared their respective branded counterparts while having essentially equivalent effectiveness.

Popularity of Allegra and Claritin

Fexofenadine, more commonly recognized under the brand name Allegra, was estimated to have been prescribed to about 4.1 million people in the US in 2020. Fexofenadine accounted for just over 9% of antihistamine prescriptions in the US. It is classified as a second-generation antihistamine known for fewer side effects related to drowsiness and sedation compared to first-generation antihistamines.

Loratadine, including brand versions such as Claritin, was prescribed to approximately 5.8 million people in the USA in 2020. In the US, loratadine accounts for around 13% of all antihistamine prescriptions and has remained one of most popular choices due its non-drowsy formula and once-a-day dosing convenience. The prevalence of loratadine has been relatively steady over the last decade with slight increases seen during peak allergy seasons annually.


Both Allegra (fexofenadine) and Claritin (loratadine) have a long-standing record of usage in patients suffering from allergies, supported by numerous clinical studies indicating they are more effective than placebo treatments. Both drugs can be used independently or together, but this depends on the careful consideration of a physician as drug interactions may occur. Due to their different mechanisms of action, with Allegra blocking histamine receptors and Claritin acting primarily on peripheral H1-receptors, they tend to be prescribed under different circumstances.

Allegra might be considered first for patients who require fast relief since it works within an hour whereas Claritin typically takes two to three hours to start working.

Both medications are available in generic form which represents substantial cost savings especially for those paying out-of-pocket. Both Allegra and Claritin work best when taken continuously during allergy season rather than sporadically so there may be an adjustment period where effects aren't noticeable immediately.

The side effect profile is similar between the two drugs, both being generally well-tolerated with minimal sedative effects due to their second-generation antihistamine status. For both medications, patients should closely monitor any adverse reactions such as dry mouth or urinary retention and seek medical help if these worsen or persist over time.