HISNEX

Each tablet contains 120 /180 mg of Fexofenadine Hydrochloride Antihistamines for systemic use.

Pharmacodynamics Properties

• Antihistamines for systemic use.


• Mechanism of Action: Fexofenadine hydrochloride is a non-sedating H₁ antihistamine. Fexofenadine is a pharmacologically active metabolite of terfenadine.


• Clinical Efficacy and Safety: Human histamine wheal and flare studies following single and twice daily doses of fexofenadine hydrochloride demonstrate that the medicinal products exhibits an antihistaminic effect beginning within one hour, achieving maximum at 6 hours and lasting 24 hours. There is no evidence of tolerance to these effects after 28 days of dosing. A positive dose-response relationship between doses of 10 mg to 130 mg taken orally was found to exist. In this model of antihistaminic activity, it was found that doses of at least 130 mg were required to achieve a consistent effect that was maintained over a 24 hour period. Maximum inhibition in skin wheal and flare areas was greater than 80%. Clinical studies conducted in seasonal allergic rhinitis have shown that a dose of 120 mg is sufficient for 24 hour efficacy.
  
  No significant differences in QT_c, intervals were observed in seasonal allergic rhinitis patients given fexofenadine hydrochloride up to 240 mg twice daily for 2 weeks when compared to placebo. Also, no significant change in QT_c intervals was observed in healthy subjects given fexofenadine hydrochloride up to 60 mg twice daily for 6 months. 400 mg twice daily for 6.days and 240 mg once daily for 1 year, when compared to placebo. Fexofenadine at concentrations 32 times greater than the therapeutic concentration in man had no effect on the delayed rectifier K⁺ channel cloned from human heart.
  
  Fexofenadine hydrochloride (10 mg/kg per orally) inhibited antigen induced bronchospasm in sensitized guinea pigs and inhibited histamine release at supra-therapeutic concentrations (10- 100 µM) from peritoneal mast cells.

• Absorption: Fexofenadine hydrochloride is rapidly absorbed into the body following oral administration, with T_max occurring at approximately 1-3 hours post dose. The mean C_max value was approximately 427 ng/ml following the administration of a 120 mg dose once daily.

• Fexofenadine is 60-70% plasma protein bound.

• Distribution: Fexofenadine is 60-70% plasma protein bound.
• Biotransformation and Elimination: Fexofenadine undergoes negligible metabolism (hepatic or non-hepatic), as it was the only major compound identified in urine and faeces of animals and man. The plasma concentration profiles of fexofenadine follow a bi-exponential decline with a terminal elimination half-life ranging from 11 to 1hours after multiple dosing. The single and multiple dose pharmacokinetics of fexofenadine are linear for oral doses up to 120 mg BID. A dose of 240 mg BID produced slightly greater than proportional increase (8.8%) in steady state area under the curve, indicating that fexofenadine pharmacokinetics are practically linear at these doses between 40^-mg and 240 mg taken daily. The major route of elimination is believed to be via biliary excretion while up to 10% of ingested dose is excreted unchanged through the urine.
• Preclinical Safety Data : 

  Dogs tolerated 4 mg/kg administered twice daily for 6 months and showed no toxicity other than occasional emesis. Also, in single dose dog and rodent studies, no treatment-related gross findings were observed following necropsy.

  Radiolabelled fexofenadine hydrochloride in tissue distribution studies of the rat indicated that fexofenadine did not cross the blood brain barrier.

  Fexofenadine hydrochloride was found to be non-mutagenic in various in vitro and in vivo mutagenicity tests.

  The carcinogenic potential of fexofenadine hydrochloride was assessed using terfenadine studies with supporting pharmacokinetic studies showing fexofenadine hydrochloride exposure (via plasma AUC values). No evidence of carcinogenicity was observed in rats and mice given terfenadine (up to 1 mg/kg/day).

  In a reproductive toxicity study in mice, fexofenadine hydrochloride did not impair fertility, was not teratogenic and did not impair pre- or postnatal development.

Fexofenadine does not undergo hepatic biotransformation and therefore will not interact with other medicinal products through hepatic mechanisms. Co-administration of fexofenadine hydrochloride with erythromycin or ketoconazole has been found to result in a 2-3 times increase in the level of fexofenadine in plasma. The changes were not accompanied by any effects on the QT interval and were not associated with any increase in adverse reactions compared to the medicinal products given singly.

Animal studies have shown that the increase in plasma levels of fexofenadine observed after co-administration of erythromycin or ketoconazole, appears to be due to an increase in gastrointestinal absorption and either a decrease in biliary excretion or gastrointestinal secretion, respectively.

No interaction between fexofenadine and omeprazole was observed. However, the administration of an antacid containing aluminum and magnesium hydroxide gels 1minutes prior to fexofenadine hydrochloride caused a reduction in bioavailability, most likely due to binding in the gastrointestinal tract. It is advisable to leave 2 hours between administration of fexofenadine hydrochloride and aluminum and magnesium hydroxide containing antacids.

Theraputic Indication

HISNEX 120mg /180mg tablet is indicated in adults and children 12 years and older for the relief of symptoms associated with seasonal allergic rhinitis.

• Posology
• Adults
• The recommended dose of fexofenadine hydrochloride for adults is 120 mg once daily taken before a meal. Fexofenadine is a pharmacologically active metabolite of terfenadine.
• Pediatric population
• Adolescents aged 12 years and over
• The recommended dose of fexofenadine hydrochloride for adolescents aged 12 years and over is 120 mg /180mg once daily taken before a meal.
• Children under 12 years of age
• The efficacy and safety of fexofenadine hydrochloride 120 mg /180mg has not been studied in children under 12.
• Special Populations
• Studies in special risk groups (elderly, renally or hepatically impaired patients) indicate that it is not necessary to adjust the dose of fexofenadine hydrochloride in these patients.
• Method of Administration
• Fexofenadine hydrochloride tablet is for oral use.

The following frequency rating has been used, when applicable:

• Very common ≥1/10
• Common ≥1/100 to <1/10
• Uncommon ≥1/1,000 to <1/100
• Rare ≥1/10,000 to <1/1,000
• Very rare <1/10,000;
• 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
• headache, drowsiness, dizziness
• Gastrointestinal disorders
• nausea
• General disorders and administration site conditions
• 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)
• Hypersensitivity reactions with manifestations such as angioedema, chest tightness, dyspnea, flushing and systemic anaphylaxis
• Insomnia, nervousness, sleep disorders or nightmares/excessive dreaming (paroniria)
• Tachycardia, palpitations
• Diarrhoea
• Rash, urticaria, pruritus
• Overdose
• Dizziness, drowsiness, fatigue and dry mouth have been reported with overdose of fexofenadine hydrochloride. 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 fexofenadine hydrochloride has not been established.
• Standard measures should be considered to remove any unabsorbed medicinal product. Symptomatic and supportive treatment is recommended. Hemodialysis does not effectively remove fexofenadine hydrochloride from blood.

As with most new medicinal products there is only limited data in the elderly and renally or hepatically impaired patients. Fexofenadine hydrochloride should be administered with care in these special groups. Patients with a history of or ongoing cardiovascular disease should be warned that, antihistamines as a medicine class, have been associated with the adverse reactions, tachycardia and palpitations.

• Pregnancy : 

  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.

• Breast-Feeding : There are no data on the content of human milk after administering fexofenadine hydrochloride. However, when terfenadine was administered to nursing mother’s fexofenadine was found to cross into human breast milk. Therefore fexofenadine hydrochloride is not recommended for mothers breast-feeding their babies.
• Fertility : 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 (see section 3).
• Effects on Ability to Drive and Use Machines : On the basis of the pharmacodynamics profile and reported adverse reactions it is unlikely that fexofenadine hydrochloride tablets will produce an effect on the ability to drive or use machines. In objective tests, fexofenadine has been shown to have no significant effects on central nervous system function. This means that patients may drive or perform tasks that require concentration. However, in order to identify sensitive people who have an unusual reaction to medicinal products, it is advisable to check the individual response before driving or performing complicated tasks.

• Hypersensitivity to the active substance or to any of the excipients