More than 50 million Americans suffer allergies each year. If you’re one of them, you’ve probably treated your symptoms with the myriad allergy medications sold on drugstore shelves. You may have found yourself overwhelmed by all the varieties.
Each active ingredient in these allergy medicines works differently, with pros and cons to each. To understand how different allergy medicines compare in terms of safety and effectiveness, it helps to know how they work and what each does differently.
Many over-the-counter allergy medications fall under the category of antihistamines. These medications combat the body’s production of chemicals called histamines, which your body makes when it comes into contact with environmental triggers like pollen, animal dander, ragweed and dust mites. Those histamines are to blame for unpleasant symptoms like a runny or stuffy nose, itchy eyes and even rash-like hives on your skin. That’s why medicines that reduce or block histamines can also alleviate certain allergy symptoms.
However, there’s a downside: Some antihistamine medications can have a sedative effect, which may not make them a viable option for people who need to put in a full day’s work or operate heavy machinery (like driving a car).
Not all allergy medicines contain antihistamine ingredients. Nasal decongestant medicines like pseudoephedrine (Sudafed), for example, are often used to relieve allergy-related congestion. Some allergy medications will combine both nasal decongestant and antihistamine ingredients. For allergy sufferers who forgo antihistamines and decongestants altogether, corticosteroid creams and sprays are also a common over-the-counter option for treating allergy-induced sinus inflammation and skin itching.
In short, there are a lot of medications for allergy sufferers to choose from. We asked two board-certified allergists to weigh in on a few of the most common varieties of allergy medication to help you find the best option for your symptoms and lifestyle.
Diphenhydramine
Diphenhydramine is the active ingredient in Benadryl. It’s one of the oldest antihistamine medications on the market, dating back to the mid-1940s. Because of this and the pharmaceutical technology it uses, you may see it classified as a first-generation antihistamine.
Like other antihistamine drugs in the first-generation category, diphenhydramine blocks histaminic and muscarinic receptors in the body’s brain and spinal cord — the culprits behind those pesky symptoms. Despite its status as the old, gold standard of allergy medication, the jury’s out on whether first-generation antihistamines, including diphenhydramine, offer any distinct advantages over their second-generation counterparts. In large amounts, this medication and others like it can even be toxic.
“It shouldn’t be used daily, ideally,” says Dr. Payel Gupta, a New York City allergist. “And [diphenhydramine] can make some people very sleepy.”
Dallas–Fort Worth–area allergist Dr. Nana Mireku agrees. “First-generation antihistamines such as diphenhydramine have more of a sedation effect than second-generation antihistamines,” she says.
Loratadine
This second-generation antihistamine is sold under the brand name Claritin. Loratadine mainly blocks histaminic receptors instead of both histaminic and muscarinic receptors. And unlike first-generation antihistamines, it doesn’t cross the brain-blood barrier.
Loratadine hit pharmacy shelves in the 1980s, and compared to its predecessors, it’s faster-acting and longer-lasting. But loratadine’s biggest perk is that it causes less drowsiness than first-generation antihistamines like diphenhydramine.
“It might not be as effective for people as the other antihistamines,” says Gupta. “But it shouldn’t cause as much sedation.”
Cetirizine
Sold in the US under the brand name Zyrtec, cetirizine is another second-generation antihistamine medication. Like loratadine, the drug’s allergy-fighting properties remain active for up to 24 hours. Cetirizine is even faster-acting than loratadine, requiring only about an hour to take effect.
Mireku notes that, like other antihistamines, cetirizine is very effective at alleviating nasal itching, sneezing and runny nose symptoms from allergies. Some studies have also found this drug more effective than other antihistamines at treating hives. But Gupta warns that cetirizine has a higher likelihood of causing drowsiness than some other second-generation antihistamines.
Fexofenadine
Fexofenadine is a second-generation antihistamine sold under the brand name Allegra in the US. It’s recommended for treating mild to moderate nasal allergy symptoms, and it has some serious perks over some of its competition — namely its minimal risk of drowsiness, according to Gupta. Fexofenadine is also potentially safer than other antihistamines for breastfeeding parents to use.
There are some drawbacks. Fexofenadine mixes poorly with juices from multiple fruits; apple juice, grapefruit juice and orange juice should be avoided when taking the drug. It is also not recommended that pregnant people take this medication.
Fluticasone
A nasal steroid spray sold under the brand name Flonase in the US, fluticasone works by attacking inflammation in the nasal cavity. It takes a little longer to relieve allergy symptoms than some antihistamines, but the effects tend to be longer-lasting. Mireku points out that it’s also quite effective in treating itchy, watery eyes — a detail that’s sometimes overlooked, as the medication is delivered nasally.
As for potential risks, Gupta says the localized delivery of fluticasone (it’s a spray you apply right where you need it) makes it safe for long-term use. But, she adds, “Patients with a history of cataracts or glaucoma should check in with their eye doctor to ensure that using a nasal steroid is okay, as they can potentially worsen these conditions.”