Compare Allegra D vs. Benadryl

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Allegra D
(Pseudoephedrine / Fexofenadine)

Benadryl
(Diphenhydramine)

Treats allergy symptoms and congestion. Allegra D (Pseudoephedrine / Fexofenadine) is a combination allergy medicine that's useful if you have congestion and runny nose.Treats allergy symptoms and helps you sleep. Benadryl (Diphenhydramine) is great for allergies, but curl up on the couch after taking it and get ready for a nap.
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Reviews & ratings
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Reviews for Benadryl (Diphenhydramine)
85%
+18% vs. Allegra D (Pseudoephedrine / Fexofenadine)
57%
10% vs. Allegra D (Pseudoephedrine / Fexofenadine)
8%
8% vs. Allegra D (Pseudoephedrine / Fexofenadine)
Side effects
Allegra DBenadryl
  • Back pain 2%
More Allegra D side effects »

We haven’t found good data for Benadryl side effects.

FDA side effect reports for Benadryl »
How it works
Allegra DBenadryl
Allegra D (Pseudoephedrine / Fexofenadine) is a combination medicine that relieves allergy symptoms. Fexofenadine (an antihistamine) prevents allergy symptoms like runny nose, sneezing, and itching. Pseudoephedrine (a decongestant) clears your sinuses.Benadryl (Diphenhydramine) is an antihistamine. It blocks histamine, a chemical that causes congestion, itching, and other allergic reactions. It also makes you sleepy.
Type of medication
Allegra DBenadryl
DecongestantAntihistamine
2nd generation
Prescription or OTC
Antihistamine
1st generation
Prescription or OTC
Available as
Allegra DBenadryl
  • Extended release
  • Pill
  • Oral solution
  • Cream, gel, or ointment
Used for (click to learn more)
Allegra DBenadryl
Risk factors for serious side effects
Allegra DBenadryl
  • Taking with alcohol
  • Taking other medicines that make you less alert
  • History of high blood pressure
  • History of heart problems
  • Age 65 or older
  • History of seizure
  • Women of childbearing age
Detailed Allegra D (Pseudoephedrine / Fexofenadine) risks & warnings »
  • Using other drugs with the same ingredients
  • Age 65 years or older
  • Taking with alcohol
  • Taking other medicines that make you less alert
  • Children age 6 years and younger
  • Enlarged prostate
  • History of bladder problems
  • Glaucoma
  • Nursing mothers
Detailed Benadryl (Diphenhydramine) risks & warnings »
Pregnancy category
Allegra DBenadryl
CFDA pregnancy category (Weigh risks vs. benefits)

Research studies with animals found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

See the FDA package insert
BFDA pregnancy category (Probably safe)

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

See the FDA package insert
Alcohol
No specific alcohol-related info.
  • Don't take it with alcohol or other drugs that make you sleepy.
Food
No specific food-related info.No specific food-related info.
Kidneys and liver
  • Talk to your doctor if you have high blood pressure or kidney problems before using it.
No specific kidneys and liver-related info.
Sex
No specific sex-related info.No specific sex-related info.
Sleep
  • The antihistamine (fexofenadine) can cause dizziness, drowsiness, dry eyes/mouth, and constipation.
  • The decongestant (pseudoephedrine) can make your blood pressure higher and can make it harder to sleep.
  • Avoid taking it close to bedtime to prevent trouble sleeping.
  • Benadryl (Diphenhydramine) makes you tired, so take it before you go to sleep.
  • People age 65 years and older have a higher risk of side effects from taking antihistamine medications like Benadryl (Diphenhydramine). Watch for changes in vision, severe dry mouth, trouble urinating, or constipation. The drowsiness caused by Benadryl (Diphenhydramine) can make you "unsteady" on your feet, leading to a higher chance of falls.
Weight
No specific weight-related info.No specific weight-related info.
Upsides and benefits
Allegra DBenadryl
  • Available without a prescription in the drugstore.
  • It has two medications that work in different ways to help relieve nasal symptoms.
  • The antihistamine (fexofenadine) is useful for relieving itchy eyes, runny nose, or constant sneezing.
  • The decongestant (pseudoephedrine) is very good at relieving congestion.
  • Benadryl (Diphenhydramine) is often better than other antihistamines at treating allergy symptoms and hives.
  • It can provide quick relief of allergy symptoms for both kids and adults.
  • It makes you sleepy, so it'll help if your allergies are bothering you at night.
  • The effects wear off in 4 to 6 hours, so side effects don't last that long.
  • It comes as a tablet, capsule, liquid, and quick dissolving tablet.
Downsides and risks
Allegra DBenadryl
  • Has more side effects than Allegra since it has pseudoephedrine in it.
  • The antihistamine (fexofenadine) can cause dizziness, drowsiness, dry eyes/mouth, and constipation.
  • The decongestant (pseudoephedrine) can make your blood pressure higher and can make it harder to sleep.
  • You must show a photo ID to buy this from behind the pharmacy counter. There's a maximum limit on how much you can buy in the pharmacy at a time.
  • Benadryl (Diphenhydramine) makes you more tired than Claritin, Allegra, or Zyrtec.
  • You shouldn't drive after taking Benadryl (Diphenhydramine) until you know how it affects you.
  • Talk to a pediatrician before giving Benadryl (Diphenhydramine) to a child.
  • It can increase the risk of falls, so elderly people shouldn't use Benadryl (Diphenhydramine).
  • Don't use Benadryl (Diphenhydramine) if you are breastfeeding.
Tips from our pharmacists for people taking the medication
Allegra DBenadryl
  • It works best if you have nasal congestion and a runny nose.
  • Take on an empty stomach, 1 hour before eating or 2 hours after eating.
  • Shouldn't be used in kids younger than 12 years old.
  • Avoid taking it close to bedtime to prevent trouble sleeping.
  • Can cause dizziness, headache, or a fast heartbeat.
  • Talk to your doctor if you have high blood pressure or kidney problems before using it.
  • If symptoms get worse or you need to use it for more than a few weeks, talk with your doctor.
  • Take it as needed every 4 to 6 hours.
  • Benadryl (Diphenhydramine) can make you dehydrated, so avoid this side effect by drinking plenty of fluids.
  • Benadryl (Diphenhydramine) makes you tired, so take it before you go to sleep.
  • Don't take it with alcohol or other drugs that make you sleepy.
  • If you need to use it for more than a few weeks, talk with your doctor. A different medication might work better for you long-term.
  • If you only have itchy or watery eyes, try using just an antihistamine eye drop.
Learn more
More about Allegra DSide effectsReviews & ratingsAlternativesFDA package insert
More about BenadrylSide effectsReviews & ratingsAlternativesFDA package insert