HISTAFIX
Each film coated tablets contains:
(Fexofenadine Hydrochloride USP 120 mg / 180 mg)
Composition
Each film coated tablets contains:
(Fexofenadine Hydrochloride USP 120 mg / 180 mg)
Dosage Form
Tablet for Oral Use
Pharmacodynamics
Fexofenadine is considered an “inverse agonist” of the H1 receptor because it binds to and stabilizes the inactive form of the receptor, preventing its activation and subsequent downstream effects. It has a potent and selective affinity for H1 receptors. Fexofenadine does not cross the blood-brain barrier and thus is unlikely to cause significant CNS effects.
Pharmacokinetics
Absorption: Fexofenadine is rapidly absorbed, attaining peak plasma concentrations one hour after oral administration at 1 hour for the oral suspension and 1.5 hours for the tablet. Maximum histamine inhibition is achieved approximately 1–2 h after administration.
Distribution: Fexofenadine has approximately 60% to 70% plasma protein binding. Fexofenadine binds primarily with albumin and alpha-1 acid glycoprotein. Fexofenadine shows no receptor occupancy in the CNS at clinically relevant doses.
Metabolism &Excretion: Fexofenadine undergoes minimal hepatic metabolism. Fexofenadine is mainly excreted in feces via biliary excretion (80%).
Half Life: In healthy volunteers, the mean elimination half-life is approximately 14.4 hours after administering fexofenadine 60 mg twice.
Indications
- Seasonal allergic rhinitis characterized by symptoms including nasal itching, sneezing, rhinorrhea, and nasal congestion
- Chronic idiopathic urticaria
- Hives
Other Information
ADVERSE EFFECTS: The most frequently occurring side effects are drowsiness, fatigue, and dry mouth, which may occur in larger doses.
DOSAGE AND ADMINISTRATION: One tablet once daily
CONTRAINDICATIONS:
- Hypersensitivity to fexofenadine or any of its components is the only true contraindication to this medication’s use
WARNINGS AND PRECAUTIONS
- Caution is necessary when treating patients with renal disease
- There is no significant interaction with fexofenadine and concomitant use of alcohol or food. However, bioavailability decreases when used with grapefruit, apple, or orange juice
- In animal models, fexofenadine has been shown to cause low birth weight and is currently a category C medication in pregnancy. Alternatives for symptom relief of allergic rhinitis include Loratadine and Cetirizine
- Fexofenadine might decrease milk production, especially if used with pseudoephedrine. While breastfeeding an infant, monitor for possible irritability and jitteriness
Pregnancy Category: C
Drug Interaction:
- Betahistine can decrease the therapeutic potential of fexofenadine
- Pilolisant is a histamine-3 receptor antagonist and inverse agonist approved for narcolepsy. Concurrent use of antihistamines should be avoided.
- Concurrent administration of Apalutamide with Fexofenadine, decreases the AUC of Fexofenadine by 30%, which may result in loss of efficacy of Fexofenadine.