Over-the-counter medication · Second-Generation Antihistamine
fexofenadine
Also sold as Allegra. This medicine treats hives and itching caused by hives.
Data updated 2026-05-15
- 19,831
- FDA reportsModerately reported
- 1
- InteractionFew interactions
- $0.23
- Generic price (NADAC)
What the data shows
fexofenadine (Allegra) is an over-the-counter Second-Generation Antihistamine, reported at a middle-of-the-pack volume (19,831 FDA reports), with 1 documented drug interaction.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
fexofenadine (Allegra) is an over-the-counter Second-Generation Antihistamine. This medicine treats hives and itching caused by hives.
Fexofenadine (Allegra) is an antihistamine medicine. It helps reduce hives and relieve itching.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.23/unit
Generic Available
Yes (19 manufacturers)
Pricing data from NADAC (CMS), effective December 25, 2024. Compare all drug costs →
What it does
This medicine treats hives and itching caused by hives.
Common side effects
Headache, Fatigue, Nausea
Key warnings
No specific warnings noted. Always follow your prescriber's instructions.
The sections below are summarized in plain English from fexofenadine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Fexofenadine blocks histamine in your body. Histamine is a natural substance that causes allergy symptoms. By blocking histamine, fexofenadine reduces itching and hives.
How to Take It
Adults and children 12 years and older should take one 180 mg tablet once a day with water. Do not take more than one tablet in 24 hours. Children under 12 years old should not use this medicine. If you are 65 or older, or have kidney disease, ask your doctor before using.
This is a plain-language summary of fexofenadine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if fexofenadine will harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if fexofenadine passes into breast milk, so talk to your doctor if you are breastfeeding.
This is a plain-language summary of fexofenadine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. Do not take two doses at the same time.
This is a plain-language summary of fexofenadine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store between 68° and 77°F (20° and 25°C) and protect from excessive moisture.
Side Effects (from patient reports)
Based on 19,831 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for fexofenadine, by number of reports
- Headache
Headache
878 reports
- Tiredness
Tiredness
858 reports
- Feeling sick to your stomach
Feeling sick to your stomach
778 reports
- Itching
Itching
765 reports
- Took an extra dose
Took an extra dose
700 reports
- Diarrhea
Diarrhea
693 reports
- Feeling dizzy
Feeling dizzy
647 reports
- Rash
Rash
605 reports
- Sleepiness
Sleepiness
597 reports
- Difficulty breathing
Difficulty breathing
589 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for fexofenadine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where fexofenadine sits
fexofenadine has more FDA adverse-event reports than 54% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is fexofenadine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 19,831 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
19,831
Reports Mentioning Death
549
2.8% of reports — not proof of cause
Hospitalization Reports
2,701
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | HEADACHE | 878 |
| 3 | FATIGUE | 858 |
| 4 | NAUSEA | 778 |
| 5 | PRURITUS | 765 |
| 6 | EXTRA DOSE ADMINISTERED | 700 |
| 7 | DIARRHOEA | 693 |
| 9 | DIZZINESS | 648 |
| 10 | RASH | 605 |
| 11 | SOMNOLENCE | 597 |
| 12 | DYSPNOEA | 589 |
| 13 | COUGH | 555 |
| 14 | INSOMNIA | 530 |
| 15 | PAIN | 488 |
| 16 | FEELING ABNORMAL | 485 |
| 18 | MALAISE | 451 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Known Drug Interactions
Additionally, no dosage adjustment for substrates of CYP2D6 (e.g., dextromethorphan), CYP3A4 (e.g., lovastatin), CYP2B6 (e.g., bupropion), BCRP (e.g., rosuvastatin), or P-gp (e.g., fexofenadine) is required when administered concomitantly with REXULTI.
Mechanism: Brexpiprazole does not affect the transport protein responsible for moving fexofenadine through your body.
What to do: These medications can be used together safely without any adjustment to your dosage.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
What should I do if the foil seal under the cap is broken?
Can children under 12 take this medicine?
Can I take more than one tablet a day?
What if I have kidney problems?
Can older adults take this medicine?
Will this medicine prevent allergic skin reactions?
How often should I take this medicine?
What is the strength of each tablet?
Should I take this medicine with food?
What do I do if I accidentally take an extra dose?
What are the common side effects of fexofenadine?
Does fexofenadine interact with other medications?
What drug class is fexofenadine?
Is fexofenadine safe during pregnancy?
Related Medications in Second-Generation Antihistamine
Other drugs grouped near fexofenadine - same-class peers and common alternatives.
azelastine
Astelin, Astepro
Azelastine nasal spray is an antihistamine medicine.
Compare with fexofenadine →
budesonide nasal
Rhinocort
Rhinocort is a nasal spray that helps relieve allergy symptoms.
Compare with fexofenadine →
cetirizine
Zyrtec
Cetirizine (Zyrtec) is an antihistamine medicine.
Compare with fexofenadine →
chlorpheniramine
Chlor-Trimeton
Chlorpheniramine is an antihistamine medicine.
Compare with fexofenadine →
ciclesonide nasal
Omnaris, Zetonna
Omnaris Nasal Spray is a medicine that helps treat allergy symptoms in your nose.
Compare with fexofenadine →
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
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Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
What the FDA Data Shows for fexofenadine
The FDA label for fexofenadine (sold under brand names such as Allegra) classifies it as an over-the-counter product in the Second-Generation Antihistamine class. This medicine treats hives and itching caused by hives. Official labeling lists 3 commonly reported side effects, including Headache, Fatigue, Nausea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 19,831 voluntary reports. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.23.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: December 19, 2025
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages