This page contains brief details about the drug , it's indication, dosage & administaration, mechanism of action, related brands with strength, warnings and common side effects.

Background and Date of Approval

Fexofenadine was first approved by the U.S. Food and Drug Administration (FDA) in 1996. It was initially approved for prescription use under the brand name Allegra. 

Mechanism of Action of undefined

Fexofenadine work as a selective histamine H1 receptor antagonist. When the body is exposed to allergens, such as pollen or pet dander, it triggers the release of histamine. Histamine binds to specific H1 receptors located on cells in the respiratory system, skin, and mucous membranes, leading to the manifestation of allergy symptoms like sneezing, itching, and nasal congestion. It works by competitively blocking these H1 receptors, preventing histamine from attaching to them and inhibiting its effects. By doing so, this medication effectively reduces the symptoms of allergies, providing relief from sneezing, runny nose, itchy eyes, and other allergic reactions. 

Uses of undefined

Fexofenadine relieves allergy symptoms, including sneezing, runny nose, itchy/watery eyes, and itching of the nose or throat. It is commonly used for seasonal and perennial allergic rhinitis, chronic urticaria, and other allergic reactions.

undefined Drug administaration and Dosage available

Fexofenadine is typically taken orally in tablet form, with or without food. The dosing may vary based on the specific formulation and strength of the medication, so it's crucial to follow the instructions provided by the healthcare provider. It is essential to swallow the tablet and not crush or chew it. 

Warnings, Precautions and Side Effects of undefined


Fexofenadine carries several warnings that should be considered before use. Serious allergic reactions, including anaphylaxis, can necessitate immediate medical attention if symptoms like difficulty breathing or facial swelling occur. While fexofenadine is non-sedating for most people, some individuals may experience drowsiness or dizziness. It may interact with certain medications, including erythromycin or ketoconazole. This medication may have a minimal effect on the QT interval, which measures heart rhythm. Taking more than the recommended dose can lead to overdose symptoms, such as restlessness, rapid heart rate, and dry mouth.


Inform your healthcare provider of any pre-existing medical conditions, especially heart conditions, kidney problems, or liver disease, as they may require dose adjustments or additional monitoring while using fexofenadine. If you need to use this medication for an extended period, consult your healthcare provider regularly to monitor its efficacy and assess potential side effects.  If you have been using this medication regularly and wish to discontinue it, consult your healthcare provider. Suddenly stopping the medication may cause a recurrence of allergy symptoms.

Side Effects

Side effects of fexofenadine are generally mild and infrequent but may include headache, dizziness, nausea, dry mouth, and fatigue. Rarely, allergic reactions like skin rash, itching, or swelling may occur. Although considered non-sedating, some individuals may experience slight drowsiness or dizziness. Severe side effects are rare and may include irregular heartbeat or signs of liver problems.

Word Of Advice

Before starting fexofenadine, inform your healthcare provider about any allergies you may have or your medical history (especially related to liver or kidney problems). Avoid consuming large amounts of alcohol and grapefruit juice while on this medication, as they may interact with the medication. If you are pregnant, breastfeeding, or have any specific health concerns, consult your healthcare provider before using it. Follow the prescribed dosage and do not exceed it, and if you experience any severe or unexpected side effects, seek medical attention promptly. Regularly communicate with your healthcare provider while using it for extended periods to monitor its efficacy and assess your response to the medication.

Frequently Asked Question


  1. Goodman & Gilman’s, The Pharmacological Basis of Therapeutics, Membrane transporters and drug response, 12th edition, 2011, 110.
  2. KD Tripathi, Essentials of Medical Pharmacology, Histamine and antihistaminics, 7th edition, 2013, 166.
  3. Dr. Reddy’s Laboratories (UK), Ltd, Electronic medicines compendium (EMC), [Revised on August 2018] [Accessed on 27th July 2023],
  4. Sanofi-aventis US LLC, US Food and Drug Administration, [Revised on July 2007] [Accessed on 27th July 2023],,021963s002lbl.pdf


The drug information on this page is not a substitute for medical advice, it is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you can receive this treatment.