azelastine vs diphenhydramine
Side-by-side comparison of azelastine and diphenhydramine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Astelin, Astepro
Benadryl
Azelastine nasal spray is an antihistamine medicine. It helps relieve allergy and non-allergy nasal symptoms.
Diphenhydramine, also known as Benadryl, is an antihistamine medicine. It helps relieve allergy and cold symptoms.
This medicine treats symptoms of seasonal allergies in adults and kids 5 years and older. It also treats symptoms of vasomotor rhinitis (stuffy or runny nose not caused by allergies) in adults and teens 12 years and older. It works by blocking histamine, a substance in the body that causes allergy symptoms.
This medicine temporarily relieves symptoms from allergies or hay fever. These symptoms include sneezing, itchy nose or throat, runny nose, and itchy, watery eyes. It also helps with sneezing and runny nose caused by the common cold.
Azelastine is an antihistamine. It blocks histamine, a natural substance that your body makes during an allergic reaction. By blocking histamine, azelastine helps reduce allergy symptoms like sneezing, runny nose, and itchy eyes.
Diphenhydramine blocks histamine, a natural substance that your body makes during an allergic reaction. By blocking histamine, it reduces allergy symptoms. It can also dry up nasal passages to relieve a runny nose.
- • Bitter taste
- • Headache
- • Sleepiness
- • Nasal burning
- • Sore throat
- • Headache
- • Fatigue
- • Nausea
- The medicine did not work 1,876
- The medicine was not effective 1,155
- Tiredness 1,144
- Missed dose 889
- Headache 883
- Using the medicine for a purpose it's not approved for 7,772
- Headache 5,138
- Tiredness 5,076
- Feeling sick to your stomach 4,484
- Pain 4,014
Azelastine nasal spray can cause sleepiness. Be careful driving or operating machinery until you know how this medicine affects you. Avoid drinking alcohol or taking other medicines that can cause sleepiness while using this spray.
There are no boxed warnings for this medication.
There is limited information about the safety of azelastine nasal spray during pregnancy. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if azelastine passes into breast milk, so talk to your doctor if you are breastfeeding.
If you are pregnant or breastfeeding, talk to your doctor before using this medicine. It is important to weigh the benefits and risks with your doctor.
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How to Read This azelastine vs diphenhydramine Comparison
azelastine is classified in the Antihistamine (Nasal) drug class, while diphenhydramine sits within the First-Generation Antihistamine class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are available over the counter.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, azelastine has 5,947 submissions while diphenhydramine has 26,484. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between azelastine and diphenhydramine — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.