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Best drugs to treat seasonal allergies

We take a close look at how well antihistamines and other treatments work to relieve symptoms

Last updated: June 2015


Runny nose, sneezing, itchy and watery eyes—the symptoms of allergies can make you miserable and desperate for relief. Avoiding substances that trigger your allergies can help, but since that is not always possible, you may reach for a medication.

Several types of allergy treatments are available—allergy shots, antihistamines (pills, eye drops, and nasal sprays), cromolyn, leukotriene blockers, and nasal steroid sprays. This report focuses on second-generation antihistamine pills and nasal sprays, such as Allegra, Clarinex, Claritin, Xyzal, and Zyrtec.

But, nasal steroid sprays such as fluticasone propionate (Flonase), mometasone furoate (Nasonex), and triamcinolone acetonide (Nasacort) are considered by experts the best, first option for seasonal allergies. Both Flonase and Nasacort are recently available without a prescription. One downside is that it can take hours or even days before they start to work. And the steroid sprays must be used consistently to get the greatest benefit. Because of that, some allergy sufferers may choose instead to take one of the second-generation antihistamine medications.

And while the newer, second-generation antihistamines are generally safe and are less likely to cause sedation and drowsiness compared to the older, first-generation antihistamines, such as Benadryl Allergy (generic name diphenhydramine), Chlor-Trimeton Allergy, and Dimetapp Allergy, those problems can still occur, especially at higher doses. If you take a newer antihistamine, don’t drive or operate machinery until you know how it affects you.

The seven antihistamine drugs we evaluated for this report all work equally well at relieving allergy symptoms, with none being clearly better or safer than the others. But they differ in how much they cost—ranging from $11 to more than $200. Choosing the right medication could save you hundreds of dollars a year or more.


If you and your doctor have decided an antihistamine is appropriate for your allergy symptoms, we have selected the following as Consumer Reports Best Buy Drugs based on dosing convenience, cost, effectiveness and safety:

  • Cetirizine
  • Fexofenadine
  • Loratadine
Do you suffer from allergies? What works best for you?

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Those are all low-cost generics available in various formulations (liquid, tablet, chewables, dissolvables) without a prescription. Some people may respond well to one antihistamine while getting no benefit from another. If one of our Best Buy picks does not work for you, then try a different one.

Before you start taking an antihistamine on a regular basis, make sure you have allergies—and not a cold, for example. Some people mistakenly think they have allergies when they actually have something else entirely, such as asthma, a nasal polyp, or severe heartburn (gastroesophageal reflux disease). See your doctor for a proper diagnosis unless you have already been diagnosed with allergies.


In people who have allergies, the body’s immune system overreacts when exposed to otherwise harmless substances—animal dander, dust mites, mold spores, or pollen—by releasing excessive amounts histamine. That chemical is a part of the body’s natural defense mechanisms, and it works in part by widening blood vessels, which also causes congestion and sneezing.

Allergies are fairly common. About 17.6 million adults and 6.6 million children in the U.S. were diagnosed with allergies in 2012, according to the Centers for Disease Control and Prevention. Symptoms include nasal congestion, a runny nose, sneezing, and itchy and watery eyes.

Antihistamines work by blocking histamine, which is the main trigger of allergy symptoms in the nose, airways, and skin.

Medications called "second-generation" antihistamines have eclipsed older antihistamines, such as Benadryl, chlorpheniramine (e.g. Chlor-Trimeton Allergy); clemastine (Tavist); brompheniramine (Dimetapp); and diphenhydramine (Benadryl Allergy) for treating allergy symptoms because they are less likely to cause sedation and drowsiness. Those newer antihistamines have been widely advertised, so you might recognize some of the brand names—Allegra, Claritin, Clarinex, Zyrtec, and Xyzal.  

While the second-generation antihistamines can help relieve allergy symptoms, they usually don’t clear them up entirely. There’s also been a long-standing debate about just how much better they are than older, less expensive antihistamines and whether they’re worth the extra cost. There’s no easy answer.

Most doctors advise their patients to use the newer pills, while others think their patients do just as well taking the older, nonprescription drugs. Some people respond better to the older antihistamines than the newer ones. In addition, a patient might get relief from an older drug without much sedation.

Good to note: Studies have found slowed reaction times among some people taking the older antihistamines, even when they denied feeling drowsy. One concern is that could raise the risk for auto accidents and other incidents at home and work, although this link has not been clearly proven.

And sedation and drowsiness can still occur when taking the newer medications, especially at higher doses, although they are thought to be safer in this regard. While fewer people experience serious sedation with the newer antihistamines, the labels on these drugs still warn people not to drive or operate machinery until you know how they affect you. Most of the newer antihistamines need to be taken just once a day while the older ones must be taken two or more times a day because their effect wears off more quickly. 

We evaluated seven second-generation antihistamines—five oral medicines and two nasal sprays. All of them are available as generics, and three of the oral antihistamines are available as nonprescription over-the-counter (OTC) drugs. The drugs covered in this report are:

Generic Name

Brand Name(s)

Available as a

Prescription Generic Drug?

Available as an OTC Drug?

Oral medications


















Claritin, Alavert



Nasal sprays

Azelastine nasal


Astelin, Astepro



Olopatadine nasal spray




How well do antihistamines work?

Antihistamines lessen the symptoms of hay fever and other seasonal allergies in a majority of people, though they don’t usually relieve symptoms entirely. And some people get more relief than others. The drugs can also become less effective with long-term use.

The scientific literature comparing second-generation antihistamines against each other is not extensive—most of the studies are short-term, and only a few include large numbers of people. Our analysis shows that the drugs do not differ substantially in how well they work; symptoms are usually relieved within one to three hours and lasts for 12 to 24 hours.

Studies also suggest that the tablet and liquid forms of second-generation antihistamines—cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine—don’t differ in any consistent way in terms of effectiveness, safety, or the side effects they cause.

These medications all generally bring some relief in one to three hours but it is important to continually use them during the time you are exposed to the allergic trigger (e.g. pollen).  

Table 1. Summary of Evidence on Antihistamines

Generic Name

(Brand names)

Usual Adult Dose

Proven Effective Against Hay Fever and

Intermittent Allergies?1

Proven Effective

Against Year-round or

Persistent Allergies?2

Oral Medications



10 mg once daily





5 mg once daily





60 mg once or twice daily, or 180 mg once daily





5 mg once daily




(Alavert, Claritin)

10 mg once daily



Nasal sprays

Azelastine nasal spray/pump

(Astelin, Astepro)

One or two sprays per

nostril twice daily



Olopatadine nasal spray


Two sprays per nostril

twice daily



1. Intermittent allergies are when symptoms last fewer than 4 days a week, or less than 4 weeks a year.

2. Persistent allergies are symptoms are present more than 4 days a week and for more than 4 weeks a year.

3. Sufficient evidence was not available for fexofenadine, although it is likely effective in treating year-round or persistent allergy symptoms.

How safe are antihistamines?

In studies comparing the newer antihistamines, 15 to 25 percent of people experienced at least one side effect. (See Table 2.)

Drowsiness: The good news is that all of the newer antihistamines are less likely to cause sedation and drowsiness than older antihistamines. Specifically, studies indicate newer antihistamines cause drowsiness in fewer people than two older antihistamines, diphenhydramine and chlorpheniramine.

For the newer antihistamines, other research has found that cetirizine and levocetirizine caused sedation in more people than loratadine and desloratadine. Some other evidence suggests that cetirizine causes sedation in more people than fexofenadine. One observational study found no difference in sedation rates between loratadine and fexofenadine.

Good to know: Alcohol can exacerbate drowsiness, so skip drinking it while taking antihistamines. And use caution if driving or operating heavy or dangerous machinery while taking an antihistamine.

Table 2. Side Effects

Relatively minor—usually go away in time:

More serious—these can be dangerous and should be reported to a health-care professional:

■ Drowsiness

■ Dry mouth, nose, or throat

■ Hoarseness

■ Headache

■ Dizziness

■ Nausea

■ Rapid or pounding heartbeat

■ Unusual weakness

■ Nervousness

■ Stomach pain

■ Yellowing of the skin

■ Difficulty urinating

■ Vision problems

Rare side effects: In a very small number of people, antihistamines can cause more serious reactions, such as rapid heartbeat or heart palpitations. See a doctor if you experience such symptoms.

Two second-generation antihistamines (terfenadine and astemizole) were removed from the market because they led to a higher risk of potentially serious heart problems. Some evidence suggests that there might be a very small risk of heart problems with currently available antihistamines. A large study found that cetirizine was associated with an increased risk of heart arrhythmias, but other analyses, including a large safety analysis by the FDA, found no increased risk. Other research, however, indicated that cetirizine, desloratadine, fexofenadine, and loratadine do not pose an increased risk of arrhythmias.

Special note about nasal anithistamine sprays: Azelastine and olopatadine have been linked to changes in taste sensations, including bitterness and nasal discomfort. Olopatadine nasal spray has been linked to nose bleeding, sores in the nose, and holes in the nasal septum.  

Drug interactions: Antihistamines can interact with other medicine or dietary supplements in ways that can be dangerous. Be sure to tell your doctor about all other medication you take, even if you think it might not be important. The main drugs to be concerned about are:

  • Antifungal medications, such as ketoconazole. They can increase the effect of some antihistamines.
  • Aspirin, which in large doses can cause ringing in the ears (tinnitus), a danger sign sometimes masked by antihistamines.
  • Certain types of fruit juice, such as grapefruit juice, apple juice, and orange juice. They might make some second-generation antihistamines less effective.
  • Any drugs known to change the way the heart beats, such as citalopram or ziprasidone. They should be used cautiously if you are taking antihistamines.
  • Medications used to improve breathing, such as theophylline. They may raise the risk of antihistamines side effects.
  • Certain antibiotics, such as erythromycin. They can increase the effects of antihistamines.
  • Antacids that contain aluminum or magnesium. When taken within 15 minutes of fexofenadine, these antacids significantly decreased the effect of that antihistamine.
  • The stomach acid reducer cimetidine, which increases the effect of azelastine nasal spray.

If you take an antihistamine combined with a decongestant called pseudoephedrine, be aware that such products should be used with caution by people with high blood pressure, heart conditions, diabetes, glaucoma, or prostate disease.

People who take products that combine these drugs are more likely to have side effects, such as headaches and trouble sleeping.


Cetirizine (Zyrtec), desloratadine (Clarinex), and levocetirizine (Xyzal) have been found to be safe and effective in children as young as six months old. Evidence on the safety and efficacy of loratadine (Claritin) is limited to children two years or older. Evidence for azelastine nasal spray, fexofenadine, and olopatadine nasal spray is limited to children six years or older.

All seven second-generation antihistamines are approved for children. There is little research of good quality on how the second-generation antihistamines compare. Because of this, there is insufficient evidence to understand if any of the second-generation antihistamines are more effective at relieving allergy symptoms or pose greater safety concerns than the others. But overall, the medications are well-tolerated by children, with few kids stopping taking the medication because they have a problem with side effects.

Children might experience drowsiness when taking antihistamines. This is especially important when it comes to teenagers who drive, because drowsiness can impede the ability to operate an automobile safely.

If your child needs an antihistamine to treat hay fever or other respiratory symptoms due to allergies, we advise trying our Best Buy pick, loratadine, first. The available evidence finds loratadine is as effective as the other over-the-counter option, cetirizine, but it is less likely to cause sedation. One study in children found cetirizine and loratadine to be just as effective as first-generation antihistamines for relieving allergic rhinitis symptoms, and loratadine has been found to provide symptom relief at 5 mg to 10 mg daily. 

Age, Race, and Gender Differences

Not enough people older than 65 and people from various ethnic groups have been included in studies of antihistamines to know if the drugs affect them differently. There’s also insufficient evidence to determine if men and women respond to the drugs differently.

People age 60 and older are more susceptible to the side effects of antihistamines, especially drowsiness. People older than 70 or so are at greater risk of falls in general, and antihistamine-induced drowsiness can raise that risk. The dosage of some second-generation antihistamines (primarily Zyrtec) should be reduced in older age and for people with kidney or liver problems.

Important note for women who are pregnant: Though human studies have not been performed in pregnant women, animal studies have found that both nasal sprays can cause birth defects, so they should not be used by women who are pregnant or breast-feeding. Azelastine nasal spray caused birth defects in mouse, rabbit, and rat studies, and olopatadine nasal spray has been associated with adverse effects on fetuses in animal studies.

Pregnant or nursing women should use the second-generation antihistamines only if their doctor agrees it’s absolutely necessary. And even then, it should be limited to the oral and liquid formulations— cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine. Animal studies indicate that those second-generation antihistamines don’t increase the risk of birth defects. No clinical trials have been done in pregnant women to test the birth defect risk in those drugs.

Our 'Best Buy' picks

The newer antihistamines are comparable in terms of how well they work and how safe they are, while none of them have a distinct advantage over the others. The main difference is how much they cost (see Table 3.) Prices range from about $11 dollars per month to more than $200.

Taking effectiveness, safety, cost, and dosing convenience into account, we have selected the following antihistamines as Consumer Reports Best Buy Drugs:

  • Cetirizine
  • Fexofenadine
  • Loratadine

All are low-cost generic drugs available in various formulations (liquid, tablet, chewables, dissolving tablets) without a prescription in drug and food stores, and many small convenience stores. And all are as effective and safe as the other second-generation antihistamines.

Some people may respond well to one antihistamine while getting no benefit from another. So if cetirizine, fexofenadine, or loratadine does not work for you, then try one of the other antihistamines.

The monthly costs for our Best Buys vary considerably—see Table 3. That’s common for nonprescription drugs, so we urge you to shop around for the best price, especially if you need to take an antihistamine on a regular basis. You might want to check online as well to see which pharmacy chains offer the best prices on our Best Buys.

In addition, some of these medications may cost as little as $4 for a month’s supply through discount generic drug programs run by major chain stores, such as Kroger, Sam’s Club, Target, and Walmart.

For an even better bargain, if you take these drugs long-term, you may be able to get a three-month supply for as little as $10 through one of these programs. We note in the price chart starting below which antihistamines are available through the discount programs. Some stores, such as CVS and Walgreens, require a membership fee to participate and might charge higher prices. There might be other restrictions too, so check the details carefully to make sure your drug and dose are covered.

Table 3. Comparing the antihistamines

Other treatments

In addition to second generation antihistamines, several other medications are available. Our analysis did not include these treatments.

Nasal steroid sprays: Experts often suggest that the best, first option for treating seasonal allergies for most people is steroid sprays, such as fluticasone propionate (Flonase), mometasone furoate (Nasonex), and triamcinolone acetonide (Nasacort).

Although a 2013 analysis by the Agency for Healthcare Quality and Research found that the research comparing antihistamines and steroid sprays directly was not sufficient to show that steroid sprays are clearly superior. At the same time, other studies have found steroid sprays to be more effective. Our medical consulants say that the overall evidence suggest steroid sprays are likely better at relieving congestion and improving quality of life.  

That said, if a steroid spray doesn’t provide enough relief or you can’t tolerate the side effects—they can cause nose bleeds, sores in the nose, and in rare cases, holes in the cartilage of your nose—a second-generation antihistamine taken with the spray can often help. And if your symptoms are limited to watery, itchy eyes, then you might only need anithistamine eye drops.

Combination products: Most antihistamines, new and old, are also available in combination with a decongestant, such as pseudoephedrine. Those combination products are not included in this analysis, but decongestant products should be used with caution by people with high blood pressure, heart conditions, diabetes, glaucoma, or prostate disease. Consult a doctor if you are not sure whether you should use a combination product.

Allergy shots and other treatments: If you use any of these or have questions, consult your doctor.

  • Leukotriene blockers. There are three: montelukast (Singulair and generic); zafirlukast (Accolate); and zileuton (Zyflo)
  • Cromolyn sodium
  • Allergy shots, also known as immunotherapy
  • Antihistamine eye drops. These include products that contain only an antihistamine, such as olopatadine (Pataday), alcaftadine (Lastacaft), and ketotifen (available without a prescription), and combination products that contain both an antihistamine and a vasoconstricting agent, such as Naphcon-A, and Visine-A (naphazoline and pheniramine).

How we picked the 'Best Buys'

Our evaluation is primarily based on independent scientific reviews of the evidence on the effectiveness, safety, and adverse effects of second-generation antihistamines from the Drug Effectiveness Review Project (2010) and from the Agency for Healthcare Research and Quality (2015). The full DERP report is available here. The AHRQ report can be found here. Overall, 3,121 studies and research articles were identified and screened. From these, the analysis focused on 18 studies that provided direct evidence of comparative effectiveness or safety.

Prices for a drug can vary quite widely, even within a single city or town. The prices for prescription drugs in this report are national averages based on sales of the drugs in retail outlets. They reflect the retail cash price that would be paid for a month’s supply of each drug in April 2015. The prescription drug costs cited were obtained from a health-care information company, Symphony Health Solutions, which tracks sales of prescription drugs in the U.S. Symphony Health Solutions is not involved in Consumer Reports Best Buy Drugs analysis or recommendations.

Prices for nonprescription drugs were obtained from a nationwide sampling by Consumer Reports secret shoppers from four major chain pharmacies—CVS, Target, Walgreens, and Walmart (CVS  prices were excluded from the calculations for fexofenadine (Allegra and generic) due to lack of CVS generic price data).

Consumer Reports selected the Best Buy Drugs using the following criteria. The drug (and dose) had to:

■ Be approved by the FDA for treating allergic rhinitis

■ Be as effective as any other second-generation antihistamine

■ Have a safety record equal to or better than other second-generation antihistamines

■ Have an average price for a 30-day supply that is substantially lower than the most costly second-generation antihistamine meeting the first two criteria.


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Editor's Note:

These materials are made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multi-state settlement of consumer-fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).

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