Allergy Relief: Antihistamines vs. Decongestants

Medically Reviewed by Jennifer Robinson, MD on May 11, 2023
3 min read

Antihistamines and decongestants won't cure your allergies. But they’ll give you much-needed relief for a runny or congested nose.

Antihistamines target histamine, which your body makes during an allergic reaction.

You can take them as pills, nasal spray, or eye drops. The pills target itching, sneezing, and runny nose. The nasal sprays work on congestion, an itchy or runny nose, and postnasal drip. Some common ones are:

  • Cetirizine (Zyrtec)
  • Chlorpheniramine (Chlor-Trimeton)
  • Clemastine (Tavist)
  • Desloratadine (Clarinex)
  • Diphenhydramine (Benadryl)
  • Fexofenadine (Allegra)
  • Loratadine (Claritin)

Antihistamines can ease your symptoms, but they work best when you take them before you feel a reaction. They can build up in your blood to protect against allergens and block the release of histamines. Ask your doctor if you should start taking allergy medicine a couple of weeks before you usually have symptoms.

Decongestants cut down on the fluid in the lining of your nose. That relieves swollen nasal passages and congestion.

You can take these by mouth in pills or liquids, like pseudoephedrine. 

Some pills with decongestants are:

  • Chlorpheniramine/phenylephrine (Actifed)
  • Loratadine/pseudoephedrine (Claritin-D)
  • Phenylephrine (Sudafed PE)
  • Pseudoephedrine (Sudafed)

Some medications combine antihistamines and decongestants. Their names usually end with “-D.”

Decongestant nasal sprays are another possibility. They shrink the swelling inside your nose to make you less stuffy. And they do it fast. Some sprays are:

  • Oxymetazoline (Afrin)
  • Phenylephrine hydrochloride (Neo-Synephrine)
  • Xylometazoline (Otrivin)

There's a catch, though. If you use them more than a few days in a row, your swelling and stuffiness may get worse. This is called a "rebound reaction." You get temporary relief, but your symptoms come back worse than before.

If you use nasal decongestant sprays, limit it to 3 days max.

Nasal steroids are a type of nose spray and are often the first drugs recommended for allergies. They're a powerful way to fight stuffiness because they get to the root of the problem.

They lessen the whole allergic inflammatory process. Plus they target all your allergy symptoms, not just congestion.

Some options are:

  • Beclomethasone 
  • Fluticasone (Flonase)
  • Mometasone (Nasonex)
  • Triamcinolone (Nasacort)

If you use one, be patient. You don't get the full effect for several days or even a week. But if you use it daily, it can be very effective. 

Allergy shots: You may want to consider them if you have allergy congestion all year and medication doesn't help much. The fancy name for this kind of treatment is "immunotherapy." It gets your body used to the things that trigger your hay fever so you won't have an allergic reaction.

Allergy shots can be very effective, but they don't work quickly. You get a series of injections over several years. Each one has a small dose of the stuff that causes your allergies.

Some allergists are turning to another form of immunotherapy that doesn't use injections. You may be able to take a pill that dissolves after you put it under your tongue. Examples are Grastek, Oralair, and Ragwitek. You need to take the first one at a doctor's office, but after that you can use them at home.

Other treatments: Eye drops can help your itchy eyes and even work for problems in your nose, too. You can try:

  • Azelastine (Optivar)
  • Ketotifen (Zaditor)
  • Naphazoline (Opcon-A, Visine-A)
  • Olopatadine (Patanol)

You can also use cromolyn sodium (NasalCrom), a nasal spray that blocks histamine and reduces swelling.

Leukotriene modifiers may help, too. They're prescription drugs that block chemicals that cause swelling. Some examples are montelukast (Singulair) and zafirlukast (Accolate).

Some of these drugs need a prescription. Others don't. First try an over-the-counter brand. But check with your doctor or pharmacist to make sure you have the right medication for your symptoms. If you don't get relief, ask for something stronger.

You shouldn’t drive when you take antihistamines such as brompheniramine (Nasahist B), chlorpheniramine (Chlor-Trimeton), clemastine (Dayhist, Tavist), and diphenhydramine (Benadryl). They can make you drowsy. Others such as desloratadine (Clarinex), fexofenadine (Allegra), and loratadine (Alavert, Claritin) usually don’t.

Decongestants can also cause side effects, such as:

  • Nervousness
  • Sleeplessness
  • Increased heart rate
  • Increased blood pressure

You shouldn’t take decongestants if you have certain health issues, including high blood pressure or heart problems. If you have prostate problems that make it hard to pee, these drugs can make the problem worse.

Check drug labels for more information about side effects.