The H1 histamine receptor is responsible for mediating hypersensitivity and allergic reactions. Exposure to allergen results in the degranulation of mast cells and basophils, which then release histamine and other inflammatory mediators. Histamine binds to, and activates, H1 receptors, which results in the further release of pro-inflammatory cytokines, such as interleukins, from basophils and mast cells. These downstream effects of histamine binding are responsible for a wide variety of allergic symptoms, such as pruritus, rhinorrhea, and watery eyes.
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, and there is no evidence that it carries antidopaminergic, antiserotonergic, anticholinergic, sedative, or adrenergic blocking activity. Fexofenadine does not cross the blood-brain barrier and thus is unlikely to cause significant CNS effects.
Allergic Rhinitis-
Adults and children 12 years and older:
Tablet: 60 mg twice daily or 120 mg once daily or 180 mg once daily
In case of impaired renal function: 60 mg once daily
Children from 6 to 11 years:
Tablet: 30 mg twice daily or 60 mg once daily
In case of impaired renal function: 30 mg once daily
Children from 2 to 11 years
Suspension: 30 mg or 5 ml twice daily
In case of impaired renal function: 30 mg or 5 ml once daily
Chronic Idiopathic Urticaria-
Adults and children 12 years and older:
Tablet: 60 mg twice daily or 120 mg once daily or 180 mg once daily
In case of impaired renal function: 60 mg once daily
Children from 6 to 11 years:
Tablet: 30 mg twice daily or 60 mg once daily
In case of impaired renal function: 30 mg once daily
Children from 6 months to less than 2 years:
Suspension: 15 mg or 2.5 ml (1/2 tsp) twice daily
In case of impaired renal function: 15 mg or 2.5 ml (1/2 tsp) once daily
Children from 2 to 11 years:
Suspension: 30 mg or 5 ml (1 tsp) twice daily
In case of impaired renal function: 30 mg or 5 ml (1 tsp) once daily
* রেজিস্টার্ড চিকিৎসকের পরামর্শ মোতাবেক ঔষধ সেবন করুন'
The following frequency rating has been used, when applicable: Very common ≥1/10; Common ≥1/100 and <1/10; Uncommon ≥1/1,000 and <1/100; Rare ≥1/10,000 and <1/1,000; Very rare <1/10,000 and not known (frequency cannot be estimated from the available data). Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness. In adults, the following undesirable effects have been reported in clinical trials, with an incidence similar to that observed with placebo: Nervous system disorders- Common: headache, drowsiness, dizziness; Gastrointestinal disorders- Common: nausea; General disorders and administration site conditions- Uncommon: fatigue. In adults, the following undesirable effects have been reported in post-marketing surveillance. The frequency with which they occur is not known (cannot be estimated from available data): Immune system disorders- hypersensitivity reactions with manifestations such as angioedema, chest tightness, dyspnoea, flushing and systemic anaphylaxis; Psychiatric disorders- insomnia, nervousness, sleep disorders or nightmares/excessive dreaming (paroniria); Cardiac disorders- tachycardia, palpitations; Gastrointestinal disorders- diarrhea; Skin and subcutaneous tissue disorders- rash, urticaria, pruritus
There are no adequate data from the use of Fexofenadine hydrochloride in pregnant women. Limited animal studies do not indicate direct or indirect harmful effects with respect to effects on pregnancy, embryonal/foetal development, parturition or postnatal development. Fexofenadine hydrochloride should not be used during pregnancy unless clearly necessary.
There are no data on the content of human milk after administering Fexofenadine hydrochloride. However, when Terfenadine was administered to nursing mothers Fexofenadine was found to cross into human breast milk. Therefore, Fexofenadine hydrochloride is not recommended for mothers breast-feeding their babies. No human data on the effect of Fexofenadine hydrochloride on fertility are available. In mice, there was no effect on fertility with Fexofenadine hydrochloride treatment.
Dizziness, drowsiness, fatigue and dry mouth have been reported with overdose of Fexo. Single doses up to 800 mg and doses up to 690 mg twice daily for 1 month or 240 mg once daily for 1 year have been administered to healthy subjects without the development of clinically significant adverse reactions as compared with placebo. The maximum tolerated dose of Fexo has not been established. Standard measures should be considered to remove any unabsorbed medicinal product. Symptomatic and supportive treatment is recommended. Haemodialysis does not effectively remove Fexo from blood.
