Each tablet contains: Fexofenadine hydrochloride 120 and 180 mg, respectively.
Pharmacology: Pharmacodynamics: Fexofenadine hydrochloride is a non-sedating H1 antihistamine. Fexofenadine is a pharmacologically active metabolite of terfenadine.
Human histamine wheal and flare studies the following single and twice daily doses of fexofenadine hydrochloride demonstrate that the drug exhibits an antihistaminic effect beginning within one hour, achieving maximum at 6 hours and lasting 24 hours. There was 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 were greater than 80%.
No significant differences in QTc 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 QTc intervals was observed in healthy subjects given fexofenadine hydrochloride up to 60 mg twice daily for 6 months, 400 mg twice daily for 6.5 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 (5-10 mg/kg po) inhibited antigen induced bronchospasm in sensitized guinea pigs and inhibited histamine release at supratherapeutic concentrations (10-100 um) from peritoneal mast cells.
Pharmacokinetics: Fexofenadine hydrochloride is rapidly absorbed into the body following oral administration, with Tmax occurring at approximately 1-3 hours post dose. The mean Cmax value was approximately 427 mg/mL (following the administration of 120 mg dose daily) or 494 ng/mL (following the administration of a 180 mg dose once daily).
Fexofenadine is 60-70% plasma protein bound. 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 concentrations profiles of fexofenadine follow a bi-exponential decline with a terminal elimination half-life ranging from 11 to 15 hours 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. The major route of elimination is believed to be via biliary excretion while up to 10% if ingested dose is excreted unchanged through the urine.
Toxicology: Preclinical safety data: Dogs tolerated 450 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 150 mg/kg/day).
120-mg Tablet: Fexofenadine hydrochloride is indicated for the relief of symptoms associated with allergic rhinitis in adults and children 12 years of age and older.
180-mg Tablet: For the relief of symptoms associated with chronic idiopathic urticaria in adults and children 12 years of age and older. For the treatment of seasonal and perennial allergic rhinitis.
Adults and children aged 12 years and over: The recommended dose of Telfast is one tablet once daily.
Children under 12 years of age: The efficacy and safety of fexofenadine hydrochloride has not been studied in children under 12 years of age.
Special risk groups: 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.
There has been no reported case of an acute overdose of fexofenadine hydrochloride. Standard measures should be considered to remove any unabsorbed drug. Haemodialysis does not effectively remove fexofenadine hydrochloride from blood.
Fexofenadine hydrochloride is contraindicated in patients with known hypersensitivity to any of its ingredients.
As with most new drugs 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.
Effects on ability to drive and use machines: On the basis of the pharmacodynamic profile and reported adverse events it is unlikely that fexofenadine hydrochloride tablets will produce an effect on the ability to drive or use machines. In objective tests, Telfast 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 drugs, it is advisable to check the individual response before driving or performing complicated tasks.
No animal reproduction studies have been performed with fexofenadine hydrochloride. Supportive pharmacokinetic studies with terfenadine have been performed and show exposure to fexofenadine at the high dose level in animal reproduction studies performed with terfenadine to be higher than is achieved at the recommended clinical fexofenadine dose. In these studies no evidence of teratogenicity or effects on male fertility were observed. Effects on female fertility and on peri and post natal development were seen only at maternally toxic doses.
There is no experience with fexofenadine hydrochloride in pregnant women. As with other medications fexofenadine hydrochloride should not be used during pregnancy unless the expected benefit to the patient outweighs any possible risk to the foetus. 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.
In controlled clinical trials the most commonly reported adverse events were headache, drowsiness, nausea, dizziness and fatigue. The incidence of these events observed with fexofenadine was similar to that observed with placebo.
Fexofenadine does not undergo hepatic biotransformation and therefore will not interact with other drugs 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 events compared to the drugs 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 aluminium and magnesium hydroxide gels 15 minutes 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 aluminium and magnesium hydroxide containing antacids.
Store at temperatures not exceeding 30°C.
R06AX26 - fexofenadine ; Belongs to the class of other antihistamines for systemic use.
Tab 120 mg x 50's. 180 mg x 50's.