The L847 pill is a pink, oval, 18 mm tablet imprinted “L847,” identified as fexofenadine 180 mg, a second‑generation antihistamine used for allergy relief and hives.
It is generally a non‑drowsy option available over the counter (generic Allegra) from various store brands in the U.S. and is not a controlled substance.
What L847 is?
The L847 imprint corresponds to fexofenadine hydrochloride 180 mg, a long‑acting antihistamine for allergic rhinitis and urticaria (hives).
It blocks histamine at peripheral H1 receptors to reduce sneezing, runny nose, itchy or watery eyes, and itch from hives.
As a second‑generation antihistamine, it is designed to be less sedating than older agents.
Quick identification
Key features: pink color, oval shape, 18 mm size, with the imprint “L847.”
Products with this imprint are marketed OTC by multiple private‑label brands; L847 (NDC series ending in 847) is listed for fexofenadine 180 mg in U.S. labeling databases.
Some listings associate L847 with labelers such as Amazon.com Services LLC (NDC 72288‑0847) and Publix (NDC 56062‑847), reflecting store‑brand generics.
What it treats
L847 (fexofenadine 180 mg) relieves seasonal allergy symptoms including sneezing, runny nose, itchy or watery eyes, and itchy nose or throat.
It also helps with itching from hives; for persistent or severe hives with breathing or swallowing problems, urgent care is required.
Efficacy typically covers an entire day with once‑daily dosing in adults and adolescents per product directions.
How it works
Fexofenadine selectively antagonizes peripheral H1 receptors, reducing histamine‑mediated symptoms without significant central nervous system penetration.
Clinical effect generally begins around 2 hours after dosing and can last up to 24 hours.
This pharmacologic profile supports once‑daily use for 24‑hour allergy relief in many products.
Dosage and directions
Typical adult/adolescent dose for 24‑hour products is 180 mg orally once daily; 12‑hour formulations use 60 mg every 12 hours as directed on the label.
Pediatric dosing varies by age and formulation (liquid or ODT) and should follow manufacturer guidance or a clinician’s advice.
Those with kidney disease may need dose adjustment; labeling advises consulting a clinician before use.
How to take it
Take fexofenadine with plain water only; do not take with fruit juices because they can lower absorption and reduce effectiveness.
Avoid taking it at the same time as aluminum‑ or magnesium‑containing antacids due to reduced absorption; separate administration times.
Store at room temperature in a cool, dry place, protected from moisture.
Side effects
Common effects include headache, dry mouth, nausea or stomach discomfort, diarrhea, dizziness, and occasional drowsiness.
Serious allergic reactions are rare but require immediate medical help (e.g., swelling of face or throat, trouble breathing, hives with systemic symptoms).
Compared with first‑generation antihistamines, fexofenadine is less sedating, but individual sensitivity varies.
Warnings and precautions
Do not exceed labeled dosing, and avoid combining with other antihistamines unless advised to prevent overdose risk.
Older adults and those with kidney problems may have higher risk of side effects or require dosing guidance from a clinician.
Pregnancy and breastfeeding: human risk data are limited; some labels historically listed Category C, so decisions should be individualized with a clinician.
Interactions to avoid
Do not take with fruit juices (e.g., grapefruit, orange, apple) because they significantly reduce drug absorption.
Separate from aluminum/magnesium antacids to avoid lowered absorption and reduced symptom control.
Alcohol may increase dizziness or drowsiness risk; caution is advised if consuming alcohol.
Appearance and labeling details
L847 products are typically film‑coated, pink, oval tablets about 18 mm without a score line.
Multiple NDC entries ending in 847 designate fexofenadine 180 mg “Allergy Relief” tablets from store brands, consistent with the L847 imprint.
A Drugs.com identifier lists L847 as fexofenadine 180 mg with inactive ingredients such as croscarmellose sodium, colorants, lactose monohydrate, and titanium dioxide.
FAQs
Is L847 the same as Allegra 180 mg? Yes—L847 is a generic for Allegra’s active ingredient, fexofenadine 180 mg, used for once‑daily allergy relief.
Does L847 make people sleepy? It is generally non‑drowsy, but some individuals may still experience dizziness or drowsiness.
How fast does it work and how long does it last? Effects begin in about 2 hours and can last up to 24 hours.
When to seek medical help
Seek urgent care for hives with trouble breathing, speaking, swallowing, dizziness, or swelling of the lips, tongue, or throat.
Stop use and consult a clinician if an allergic reaction to the product occurs or if hives do not improve after 3 days or last more than 6 weeks.
In suspected overdose, contact emergency services or Poison Control immediately.
Key takeaways
- The L847 pill is fexofenadine 180 mg, a long‑acting, generally non‑drowsy antihistamine for allergy symptoms and hives.
- For best effect, take with water only, avoid fruit juices and aluminum/magnesium antacids, and follow the labeled dosing directions.
- Consider clinician guidance if pregnant, breastfeeding, older, or with kidney disease, and seek urgent help for severe allergic symptoms.