Fexten60 mg

Fexten is a second-generation (non-sedating) antihistamine indicated for the relief of symptoms associated with the following conditions:

• Seasonal Allergic Rhinitis: Relieves sneezing, rhinorrhea (runny nose), itchy/watery eyes, itchy nose, and itchy throat/palate in adults and children. This is an established, FDA-approved indication for Fexten.
• Chronic Idiopathic Urticaria: Reduces the number and size of hives (wheals) and relieves associated pruritus (itching) in patients with chronic hives of unknown cause. This is also an established, FDA-approved indication for Fexten.

Fexten treats the symptoms of these allergic conditions; it does not cure the underlying allergic tendency and does not prevent anaphylaxis.

Each tablet/capsule contains Fexofenadine Hydrochloride INN as the active ingredient, typically available in strengths of 30 mg, 60 mg, 120 mg, and 180 mg. An oral suspension containing Fexofenadine Hydrochloride 30 mg/5 mL is also available, along with pharmaceutically acceptable excipients.

Fexten is a selective, peripherally-acting histamine H1-receptor antagonist. It is the active carboxylic acid metabolite of terfenadine and belongs to the second-generation (non-sedating) class of antihistamines.

Unlike first-generation antihistamines, Fexten does not readily cross the blood-brain barrier, which accounts for its low potential to cause sedation and anticholinergic side effects at recommended doses. It is widely used for symptomatic relief of seasonal allergic rhinitis and chronic idiopathic urticaria.

Second-generation (non-sedating) antihistamine; selective peripheral histamine H1-receptor antagonist. Fexten belongs to this drug class.

Fexofenadine Hydrochloride is a selective H1-receptor antagonist. It competitively blocks the action of histamine at peripheral H1-receptors, thereby inhibiting histamine-mediated symptoms such as vasodilation, increased vascular permeability, and stimulation of sensory nerve endings that cause itching and sneezing.

Because it has low lipophilicity and is a substrate for P-glycoprotein efflux transporters at the blood-brain barrier, Fexofenadine Hydrochloride has minimal penetration into the central nervous system, resulting in a low incidence of sedation compared with first-generation antihistamines. It has no clinically significant anticholinergic (antimuscarinic) activity.

Pharmacokinetics: Peak plasma concentrations of Fexofenadine Hydrochloride are reached approximately 1-3 hours after oral administration. It is approximately 60-70% bound to plasma proteins, undergoes minimal hepatic metabolism (less than 5%), and is eliminated primarily unchanged in feces and urine (approximately 10%). The elimination half-life is approximately 14 hours in healthy adults.

Fexten tablets should be swallowed whole with a glass of water, with or without food. The oral suspension should be shaken well before use and administered using the provided measuring device. Doses of Fexten should be taken with water only; avoid administering with fruit juices (apple, orange, or grapefruit juice) as these may reduce absorption.

Fexten has clinically significant interactions with the following:

• Fruit juices (apple, orange, grapefruit): These juices inhibit intestinal drug transporters (OATP) responsible for the absorption of Fexten, which can reduce its plasma concentration and effectiveness by up to 30-40%. Dosing should be separated from these juices, and administration with water is preferred.
• Antacids containing aluminum or magnesium hydroxide: Concurrent use reduces the absorption/bioavailability of Fexten. It is recommended to separate dosing by at least 2 hours.
• Erythromycin and Ketoconazole (P-glycoprotein inhibitors): Co-administration can increase plasma concentrations of Fexten by approximately 2-3 fold; this has not been associated with QT prolongation or clinically significant adverse effects in studies, but caution is advised.

Fexten is generally well tolerated. Reported side effects include:

• Common: Headache, drowsiness (uncommon at recommended doses), dizziness, nausea, fatigue, and dyspepsia.
• Pediatric patients: Cough, upper respiratory tract infection, otitis media, and fever have been reported in clinical trials of Fexten.
• Uncommon/rare (post-marketing): Hypersensitivity reactions (rash, urticaria, pruritus, flushing), angioedema, chest tightness, dyspnea, and rare reports of tachycardia or palpitations.

Patients taking Fexten should seek medical attention if signs of a severe allergic reaction (swelling of the face/throat, difficulty breathing) occur.

Pregnancy: Data on the use of Fexten in pregnant women are limited. As with most medications, Fexten should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus. Second-generation antihistamines are generally preferred over first-generation agents when antihistamine therapy is required during pregnancy, but a physician should always be consulted before use.

Lactation: It is not known whether Fexten is excreted in human breast milk in significant amounts. Caution is advised, and use during breastfeeding should only occur under medical supervision, weighing benefits against potential risk to the infant.

Use Fexten with caution in the following situations:

• Renal impairment: Elimination of Fexten is reduced in patients with renal impairment; a lower dose is recommended (see Dosage and Administration).
• Elderly patients: May be more sensitive to effects of Fexten; generally no dose adjustment required, but use with caution given greater frequency of decreased renal/hepatic function.
• Concurrent use with fruit juices: May reduce absorption and efficacy of Fexten (see Interactions); take with water.
• Not for acute emergencies: Fexten is not indicated for the emergency treatment of anaphylaxis or acute severe urticaria/angioedema.

Fexten causes minimal sedation at recommended doses compared to first-generation antihistamines, but individual responses may vary; patients should assess their own response before driving or operating machinery.

Reported symptoms following overdose of Fexten have included dizziness, drowsiness, and dry mouth. In case of suspected overdose, seek immediate medical attention or contact a poison control center. Treatment is supportive; standard measures to remove unabsorbed drug may be considered under medical supervision. There is no specific antidote for Fexten, and it is not effectively removed by hemodialysis.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Pediatric use: The safety and efficacy of Fexten for allergic rhinitis have been established in children 2 years and older, and for chronic idiopathic urticaria in children 6 months and older, using age-appropriate doses (see Dosage and Administration). Safety and efficacy in children below these age thresholds have not been established.

Geriatric use: Clinical studies of Fexten did not identify differences in response between elderly and younger patients, but greater sensitivity in some older individuals cannot be ruled out; renal function should be considered when dosing.

Renal impairment: Reduced clearance of Fexten is observed; dose reduction is recommended (see Dosage and Administration).

Hepatic impairment: No specific dose adjustment is established, as Fexten undergoes minimal hepatic metabolism; however, caution is advised.

Duration of treatment with Fexten depends on the condition being treated: seasonal allergic rhinitis is typically treated for the duration of allergen exposure or symptom season, while chronic idiopathic urticaria may require longer-term daily use as directed by a physician, with periodic reassessment of the need for continued therapy.

Antihistamines (second-generation, non-sedating, selective H1-receptor antagonists)

Fexofenadine Hydrochloride selectively and competitively blocks peripheral histamine H1-receptors, preventing histamine from binding and triggering allergic symptoms such as itching, sneezing, rhinorrhea, and wheal/flare responses. It has minimal ability to cross the blood-brain barrier, so it produces little to no sedative or anticholinergic effect at recommended doses, distinguishing Fexofenadine Hydrochloride from first-generation antihistamines.

C

Fexten is approved for allergic rhinitis in children 2 years of age and older, and for chronic idiopathic urticaria in children 6 months of age and older, using the oral suspension or age-appropriate tablet dose. Safety and efficacy of Fexten have not been established in infants below these age limits. Dosing should always follow the age-based schedule and a physician's guidance (see Dosage and Administration).