Xyzal vs. Allegra: Differences, similarities, and which is better for you

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

Xyzal (levocetirizine) and Allegra (fexofenadine) are each second-generation antihistamines. Antihistamines are antagonists at the H1 receptor located primarily in smooth muscle tissue, vascular endothelial cells, the heart, and the central nervous system. While they do not stop the production of histamine, they do compete with it at the H1 receptor site to slow or block the histaminic effects. Histamine is responsible for allergy symptoms such as sneezing, rhinitis (runny nose), itchy eyes, nasal congestion and inflammation, skin itching, and edema.

The first-generation antihistamines, which included diphenhydramine and chlorpheniramine, were very effective at blocking histamine receptors but were short-acting and relatively sedating. Second-generation antihistamines were developed to be longer acting and less sedating to improve patient quality of life.

Second-generation antihistamines, due to their activity at the H1 receptor site, are useful in treating conditions such as allergic rhinitis due to seasonal or perennial allergies, uncomplicated skin allergies, and chronic idiopathic urticaria. Other second-generation antihistamines include Claritin (loratadine), Clarinex (desloratadine), and Zyrtec (cetirizine).

What are the main differences between Xyzal and Allegra?

Xyzal is a second-generation antihistamine available both as a prescription and over-the-counter medication. The generic drug version, levocetirizine, is also available both as a prescription and over-the-counter. Xyzal is considered a “low-sedating” antihistamine, meaning that it can cause some drowsiness, but it is not expected to interfere with motor function or mental acuity. As a prescription, Xyzal or its generic may be covered by Medicare or commercial insurance, though there may be some exceptions because it is available over-the-counter. Xyzal is available as a 5 mg oral tablet or a 2.5 mg/ml oral solution. The over-the-counter Xyzal solution may be used in children two years of age or older. As a prescription, your physician may prescribe Xyzal for a child as young as six months old.

Allegra is also a second-generation antihistamine available both as a prescription and over-the-counter. The generic drug version, fexofenadine, is also available both as a prescription and over-the-counter. Allegra is classified as a “non-sedating” antihistamine, meaning that drowsiness is not an expected side effect from taking this medication. As a prescription, Allegra or its generic may be covered by both Medicare or commercial insurance, though oftentimes it is not because it is available over-the-counter. Allegra is available as an oral tablet in strengths of 30 mg, 60 mg, and 180 mg. It is also available as a solution in the concentration of 30 mg/5 ml. For children, there is also a 30 mg dissolvable tablet. The over-the-counter Allegra suspension may be used in children two years of age or older. As a prescription, your physician may prescribe Allegra suspension for a child as young as six months old.

Conditions treated by Xyzal and Allegra

Xyzal (What is Xyzal?) is indicated for adults to treat allergic rhinitis due to perennial or seasonal allergies, uncomplicated skin allergies, and chronic idiopathic urticaria. In children, doctors may prescribe Xyzal in children as young as 6 months old for chronic idiopathic urticaria. Otherwise, children of two years of age or older may use Xyzal over-the-counter for allergic rhinitis or chronic idiopathic urticaria.

Allergic rhinitis is characterized by symptoms such as a runny nose, nasal congestion, itchy and/or watery eyes, sneezing, and skin irritation or itching. Skin allergies may manifest as raised or swollen red areas of skin (hives), rash, swelling, and itching.

Allegra (What is Allegra?) is indicated for adults to treat allergic rhinitis due to perennial or seasonal allergies, uncomplicated skin allergies, and chronic idiopathic urticaria. In children, doctors may prescribe Allegra in children as young as 6 months old for chronic idiopathic urticaria. Otherwise, children of two years of age or older may use Allegra over-the-counter for allergic rhinitis or chronic idiopathic urticaria.

Is Xyzal or Allegra more effective?

Xyzal and Allegra have been compared directly to assess their relative symptom improvement in patients with allergic rhinitis who were exposed to an offending pollen. One study placed patients in a Vienna Challenge Chamber for four hours with grass pollen, and two hours into the study, treatment was initiated with either placebo, 5 mg levocetirizine, or 120 mg of fexofenadine. Twenty-two hours after drug administration, patients were re-exposed to the pollen for an additional six hours. Researchers measured a sum score of runny nose symptoms, sneezing, itchy nose, and eyes. At two hours post-administration, both levocetirizine and fexofenadine were significantly better than placebo, but not significantly different from each other. However, at 22-24 hours post-administration, the levocetirizine group experienced a clinically significant difference in symptom improvement. This was maintained up to the 28-hour post-administration point. While both drugs were effective at symptom relief early on, levocetirizine had a longer duration of action and maintained symptom relief for a longer period of time.

Your allergist may decide which allergy medication is best for you.

Coverage and cost comparison of Xyzal vs. Allegra

Xyzal may be covered by Medicare or commercial plans, though the coverage level may vary because it is available over-the-counter. More often than not, Medicare plans do not cover drugs that are available over-the-counter. The cost of generic Xyzal as a prescription may be over $100 in some pharmacies. With a coupon from SingleCare, you may get the generic, if prescribed by a doctor, for as low as $12 for 30 tablets of the 5 mg strength.

Allegra, like Xyzal, may be covered by Medicare or commercial plans, though the coverage level may vary because it is available over-the-counter also. Without insurance, brand name Allegra may cost as much as $30, but with a SingleCare coupon, you can get it for as low as $8-$9 for 30 tablets of the 180 mg strength, if prescribed by a physician.

Get the SingleCare prescription discount card

Common side effects of Xyzal vs. Allegra

Xyzal, while considered low-sedating, may still cause drowsiness in up to 6% of patients. Patients should avoid driving, bike riding, or other hazardous activities while on Xyzal. Some patients may choose to take their Xyzal at night to minimize the limitations sleepiness may place on their daily activities.

Post-marketing monitoring of Xyzal patients has found that heart palpitations and tachycardia, or increased heart rate, may be associated with Xyzal use. Post-marketing experience has also found a link between levocetirizine and seizures and other movement disorders related to the central nervous system.

There does not appear to be a link between Allegra and either cardiac or seizure disorders as there is with Xyzal. Allegra does have a relatively high incidence of vomiting and headache.

The incidence of diarrhea appears to be much lower in Allegra as compared to Xyzal, though it does occur in both.

Second-generation antihistamines may not be as effective as first-generation antihistamines such as Benadryl (diphenhydramine) in acute allergic reactions.

The following chart is not intended to be a comprehensive list of side effects. Please consult your doctor or pharmacist for more information on side effects.

Source: Xyzal (DailyMed) Allegra (DailyMed).

Drug interactions of Xyzal vs. Allegra

Xyzal and Allegra each have many potential drug interactions, and many of those are applicable to both drugs. Antihistamines are central nervous system depressants, and many interactions center around mechanisms in the CNS. Specifically, using second-generation antihistamines such as Xyzal or Allegra with other antihistamines such as hydroxyzine or doxylamine may have a pronounced effect of CNS depression.

Symptoms of CNS depression could present as slurred speech, lack of coordination, dizziness, or difficulty conveying thoughts. The use of opioids or benzodiazepines with either Xyzal or Allegra may also enhance the occurrence of CNS depression. The use of these medications together should be avoided.

Antihistamines also have anticholinergic effects such as dry mouth, dry throat, and decreased perspiration. Some interactions may worsen these effects. The use of Xyzal or Allegra with potassium citrate may worsen the ulcerogenic effect of potassium citrate. This combination should be avoided. Nitroglycerin sublingual tablets may be less effective in a patient who takes Xyzal or Allegra due to the anticholinergic effects.

The following list of drug interactions may not contain all possible interactions. Please consult your doctor or pharmacist for a complete list.

Warnings of Xyzal and Allegra

Patients with existing kidney disease and decreased renal function should avoid using Xyzal. Physicians may adjust your dose based on a measure of your kidney function known as creatinine clearance (CrCl). Drowsiness may occur while taking Xyzal, and patients should avoid driving.

Both Xyzal and Allegra should be avoided in patients experiencing difficulty in bladder emptying. Their anticholinergic effects may make this worse.

Alcohol, also a CNS depressant, should be avoided in patients who are taking Xyzal or Allegra.

Xyzal and Allegra may be used to treat allergic rhinitis or urticaria in pregnancy. You should always consult your physician before taking medication during pregnancy.

Frequently asked questions about Xyzal vs. Allegra

What is Xyzal?

Xyzal is a low-sedating, second-generation antihistamine used to treat allergic rhinitis due to seasonal or perennial allergies, uncomplicated skin allergies, and chronic idiopathic urticaria. It is available as a tablet and an oral solution in both prescription and over-the-counter formulations.

What is Allegra?

Allegra is a non-sedating, second-generation antihistamine used to treat allergic rhinitis due to seasonal or perennial allergies, uncomplicated skin allergies, and chronic idiopathic urticaria. It is available as a tablet and an oral suspension in both prescription and over-the-counter formulations.

Are Xyzal and Allegra the same?

While they are both second-generation antihistamines, they are not exactly the same. Xyzal is more sedating than Allegra. Post-marketing data suggests a link between Xyzal and seizures as well as cardiac effects such as increased heart rate and palpitations. These effects have not been linked to Allegra.

Is Xyzal or Allegra better?

When comparing Xyzal and Allegra for their effects on allergic rhinitis induced by grass pollen, it was determined that both were equally effective shortly after dosing, but Xyzal appears to have a longer duration of action, leading to a longer-lasting relief of symptoms.

Can I use Xyzal or Allegra while pregnant?

Xyzal and Allegra are considered safe in pregnancy to treat urticaria and allergic rhinitis, though you should always consult your physician before taking these medications in pregnancy.

Can I use Xyzal or Allegra with alcohol?

Concurrent use of alcohol with either Xyzal or Allegra is not recommended as the CNS depressive effects of both substances would be enhanced. This could lead to slurred speech or dizziness.

Is Xyzal stronger than Allegra?

Xyzal and Allegra are each effective at treating allergy-related reactions, but Xyzal has a longer duration of action. This leads to a patient experiencing relief from a single dose for a longer period of time.

Why is Xyzal taken at night?

As many as 6% of patients will experience marked drowsiness when taking Xyzal, and for this reason, it is recommended to be taken at night.

Can Xyzal cause depression?

Post-marketing data has suggested that less than 1% of patients report depression as a result of taking Xyzal. This is not to be confused with the central nervous system depression, which may manifest as slurred speech, confusion, and dizziness.