Are you all stuffed up and sneezing away because of a cold? Decongestants and antihistamines can help. They come in different forms and are often mixed into combination drugs that you can buy without a prescription.
It pays to do a little homework to make sure you're picking the right medicine for your symptoms.
What Is a Decongestant?
A decongestant is a medication that helps ease nasal congestion, which happens when something irritates the lining of your nose. This can result from a cold, the flu, or allergies, for example.
A nasal decongestant helps reduce swelling in the blood vessels in your nose. This can ease the feeling of pressure in your nose, clear up a stuffy or runny nose, and help you breathe better.
While nasal decongestants can clear up symptoms such as a runny nose, they don’t address the cause of your symptoms. If a cold is causing your symptoms, for example, a decongestant won’t cure or get rid of your cold, but it can provide some relief while the cold runs its course. The common cold usually lasts 7-10 days.
Decongestants are available as pills, liquids, nasal sprays, and nasal drops.
How to find a good decongestant
Two common decongestants are pseudoephedrine and phenylephrine. However, in November 2024, the FDA proposed removing oral phenylephrine as an active ingredient in over-the-counter (OTC) nasal decongestant drug products. The FDA reviewed data and found that oral phenylephrine is not effective as a nasal decongestant, but it is safe. This means that oral drugs for nasal congestion that contain phenylephrine are safe to take, but they may not work. The FDA may issue a final order on what drugs can be marketed.
The FDA’s proposed order doesn’t apply to nasal sprays that contain phenylephrine. Those are still considered effective.
Many decongestant medications contain multiple ingredients, such as phenylephrine or pseudoephedrine, along with ingredients like dextromethorphan (to relieve cough) or acetaminophen (to relieve pain). According to the FDA, the presence of phenylephrine in a medication doesn’t affect how the other ingredients work.
You may prefer decongestants in different formulations, like nasal sprays rather than pills. If you’re looking for a pill or liquid, you might choose a medication that contains an active ingredient that’s not phenylephrine. If you’re using a decongestant nasal spray, you shouldn’t use it for more than three or four days, because it can make your symptoms worse.
Along with OTC nasal decongestants, some decongestant drugs are available only with a prescription.
What Is an Antihistamine?
An antihistamine is a type of medication that is used to relieve or prevent allergy symptoms such as runny nose, sneezing, and watery eyes.
Antihistamines work by blocking histamine — a chemical your body makes that can cause nasal congestion and other symptoms. However, some research has found that antihistamines don’t work well to treat the common cold.
Many different antihistamines exist. They include:
- First-generation antihistamines, such as brompheniramine and chlorpheniramine
- Second-generation antihistamines, such as fexofenadine and loratadine
First-generation antihistamines are known to cause drowsiness, but second-generation ones are not.
Antihistamines come in several formulations, including pills, chewable tablets, syrups, nasal sprays, and eye drops. Many antihistamines are available OTC, but some require a prescription.
Should I Take Allergy Meds During a Cold?
Although cold and flu medications often contain antihistamines, research shows that antihistamines aren’t very effective for treating symptoms of the common cold. Most experts say that histamine isn't the major cause of a runny nose when you have a cold. Even so, some antihistamines may help relieve cold symptoms in the short term.
If you’re already taking an allergy medication, it’s a good idea to check with your health care provider before choosing a cold medicine. Because some cold medications contain antihistamines, you may take too much if you combine an allergy drug with a cold remedy. The main complication of antihistamines is overdose.
Are Cold and Allergy Medicines Safe?
Cold and allergy medicines that are approved by the FDA are generally considered safe. However, they can cause problems if you have certain health conditions or take certain medications, so check with your health care provider before taking one.
If you have unmanaged high blood pressure, you shouldn’t take decongestants, because they can raise your blood pressure. You should also check with your doctor before taking a decongestant if you have:
- Diabetes
- Glaucoma
- Heart problems
- Thyroid issues
- Prostate issues
Decongestants also may interact with other medications, such as antidepressants and medications for asthma and blood pressure.
A decongestant called phenylpropanolamine (PPA) was used for years as an ingredient in many cold medicines to clear up a stuffy nose. In 2000, researchers found it was linked to an increased risk of stroke, especially in women and people assigned female at birth aged 18 to 49. The FDA then banned it from use in all prescription and OTC medications.
Antihistamines may cause complications if you have certain health conditions. Before taking an antihistamine medication, check with your doctor if you have:
- Diabetes
- Epilepsy
- Heart disease
- High blood pressure
- Glaucoma
- Prostate issues
- Hyperthyroidism
If you are pregnant or breastfeeding, check with your doctor before taking a decongestant or antihistamine. They may tell you to avoid some decongestants if you’re breastfeeding.
Side Effects of Using Allergy Medications During a Cold
The main side effect of antihistamines is drowsiness, so they can be tough to take during the day.
Common side effects of antihistamines include:
- Drowsiness, along with reduced coordination, judgment, and reaction speed
- Dry mouth or dry eyes
- Dizziness
- Headache
- Low blood pressure
- Blurry or double vision
- Constipation or difficulty peeing
- Abdominal pain
- Nausea or vomiting
- Sore throat
- Cough
- Thickening of the mucus in your airways
Decongestant side effects
Decongestants may keep you awake and are usually taken during the day. Nasal sprays are less likely to have that side effect and may be helpful at night for congestion.
Here are some common side effects of decongestants:
- Insomnia
- Nervousness or anxiety
- Restlessness
- Headaches
- Nausea
- Dizziness
- Heart palpitations
- High blood pressure
If your blood pressure is high already or you've got heart disease, check with your doctor before taking decongestants. They may be able to suggest cold medicines that don't contain decongestants.
If you take a combination cold medicine that contains an antihistamine, a decongestant, and/or another active ingredient, it may cause these or other side effects. See a health care provider right away if you have serious side effects, such as:
- Trouble breathing
- Allergic reactions, such as hives or swelling of the face, lips, or tongue
- Changes in vision
- Fast, irregular heartbeat
- Dizziness
- Seizures
Common Decongestants and Antihistamines for Colds
There are many OTC decongestants and antihistamines that can help treat your symptoms. They're sold separately or as part of a combo with other cold and pain drugs.
If you choose a combination medicine, make sure you know everything that's in it. Check to see if it has acetaminophen. If so, follow the directions on the label carefully, and don't take acetaminophen along with it because it could cause serious liver damage.
These OTC antihistamines and decongestants treat cold and allergy symptoms.
Type of Decongestant or Antihistamine Cold Medicine | Brand Name(s) | Symptoms | Possible Side Effects |
| Antihistamine (tablets, caplets, or liquid) | Benadryl Dimetane Tavist | Itchy, runny nose and eyes; sneezing; itchy throat | Drowsiness or grogginess, upset stomach, dry mouth, poor coordination and judgment, urinary retention, loss of appetite, excitability (in children) |
| Decongestant (tablets or caplets) | Sudafed | Congestion and pressure in the head, nose, and ears | Lightheadedness, wakefulness, nervousness, restlessness (jittery and shaky), increased blood pressure and heart rate; irregular heartbeat |
| Antihistamine/ decongestant/ Pain reliever (tablets, caplets, or liquid) | Advil Cold and Sinus | Itchy, runny nose and eyes; sneezing; congestion; headache | Possible antihistamine and/or decongestant side effects |
| Decongestant nose spray | Afrin Neo-Synephrine Dristan Nasal Spray | Nasal stuffiness | Might lead to "rebound" congestion from dependence on the medicine if used for more than three days |
| Antihistamine eye drops | Visine-A (Formerly OcuHist) Zaditor Opcon-A | Itchy, watery eyes; eye redness | Temporary stinging in the eyes or blurred vision; "rebound" redness of the eyes if overused |
Alternatives to Decongestants and Allergy Meds During a Cold
Sometimes, cold and allergy medications don’t do much to ease your symptoms and your cold has to run its course. Here are some alternatives to drugs that may help you feel better.
- Staying hydrated and drinking warm liquids
- Using saline nasal spray, nose drops, or a Neti pot
- Using a humidifier
- Getting plenty of rest
- Gargling with salt water
Studies on taking vitamin C and zinc have shown mixed results. For example, taking vitamin C hasn’t been shown to prevent a cold, but taking it before symptoms start may help shorten the time that you experience symptoms. Studies on zinc and cold symptoms have had mixed results, and nasal sprays that contain zinc may cause you to lose your sense of smell.
Takeaways
Both decongestants and antihistamines can relieve symptoms such as a runny or stuffy nose. But they work in different ways. Antihistamines block histamine, a chemical that causes allergy symptoms. To treat cold symptoms, research has found that antihistamines aren’t very effective. Some medications contain a combination of a decongestant and an antihistamine. If you’re not sure what to take, talk with your health care provider about your symptoms, other drugs you take, and any other health conditions you have.
FAQs on Using Allergy Meds During Cold
Can children take allergy meds during a cold?
Some children’s cold medicines contain antihistamines, which are allergy meds. But children under the age of 4 should not take over-the-counter cold medicines that contain an antihistamine or decongestant because of the risk of serious side effects. In older children, these medicines may help relieve cold symptoms, but it’s a good idea to check with a health care provider first.
What are the differences between decongestants and antihistamines?
Both decongestants and antihistamines may help relieve symptoms such as a runny nose, but they work in different ways. Decongestants reduce swelling in the blood vessels in your nose, while antihistamines block histamine, a chemical that your body makes that causes allergy symptoms such as nasal congestion.
Which is the best decongestant for colds?
The best decongestant for a cold depends on your situation, including what your symptoms are, what other health conditions you have, and what other medications you’re taking. It’s a good idea to check with your healthcare provider when choosing a decongestant.
Are antihistamines effective for cold symptoms?
Research has shown that antihistamines aren’t very effective for the common cold, but they may help relieve cold symptoms in the short term.
Can I take decongestants and antihistamines together?
Some cold medicines contain both a decongestant and an antihistamine, and they are generally considered safe to take. Usually, you can take a decongestant and an antihistamine at the same time. But because different drugs can cause different side effects and interactions with other drugs, it’s best to check with a health care provider before choosing which OTC medications to take.
