RxPRODUCT NEWS PROFILE: Allegra-D 24 Hour Tablets
Allergy sufferers have a newoption for the treatment of seasonalallergic rhinitis: Allegra-D24 Hour Extended-Release Tablets (fexofenadineHCl 180 mg and pseudoephedrineHCl 240 mg),1 manufacturedand marketed by Sanofi-Aventis.The tablet's unique Osmodex deliverysystem regulates the 24-hour release.2
Fexofenadine has gained popularityfor its nonsedating antihistaminicefficacy against seasonal allergy symptomsunlike traditional antihistamineswhich often result in significantdrowsiness and anticholinergicside effects. In many cases, thesesedating side effects present a majordeterrent to treatment. Second-generationantihistamines, such as fexofenadine,offer a reprieve from allergysymptoms without the bothersomesleepiness associated with earlier antihistamines.3
Fexofenadine exerts its antihistaminicproperties through selectiveperipheral histamine1-receptor antagonistactivity, resulting in antihistaminicactivity without sedative effects. Fexofenadinedoes not cross the bloodbrainbarrier, and in animal studies fexofenadinedid not show centralnervous system effects, anticholinergiceffects, or alpha1-adrenergic-receptorblocking effects. Fexofenadine is theactive metabolite of terfenadine.1
Pseudoephedrine, an orally activesympathetic amine, is a nasal decongestant.It is effective in reducing nasal congestionassociated with allergic rhinitis.1
Clinical studies of safety and efficacywere not performed with Allegra-D 24Hour. Instead, efficacy was based ondata extrapolated from earlier studiesfrom previously marketed Allegra 180mg and data for nasal decongestion byoral pseudoephedrine.1 Bioequivalencebetween Allega-D 24 Hour Tablets andthe concurrent administration of theindividual drug components has beenassessed in an open-label, randomized,2-treatment, 2-period, crossover study.The study found the combination formulationto be bioequivalent to theconcurrent administration of the individualdrug components.
Contraindications, Warnings,and Precautions
Patients with a history of allergic reactionto fexofenadine or pseudoephedrineshould not take Allegra-D 24Hour. Patients with narrow-angle glaucoma,urinary retention, severe hypertension,severe coronary artery disease,or idiosyncrasy to adrenergic agents arecontraindicated for treatment withAllegra-D 24 Hour. Additionally,patients taking monoamine oxidaseinhibitors (MAOIs) and those who havetaken MAOIs within the past 14 daysshould not take Allegra-D 24 Hour. Prescribersalso should avoid treatmentwith Allegra-D 24 Hour in patients withrenal insufficiency. They should usesympathomimetic amines, such as thepseudoephedrine component of Allegra-D 24 Hour, cautiously in patientswith hypertension, diabetes mellitus,ischemic heart disease, increased intraocularpressure, hyperthyroidism, orprostatic hypertrophy.1
The most commonly reported sideeffects from fexofenadine are headache, upper respiratory tract infection,and back pain. Common side effectsfrom pseudoephedrine include nervousness,excitability, restlessness, dizziness,weakness, or insomnia.1
Allegra-D 24 Hour Extended-ReleaseTablets should be swallowed whole oncea day, on an empty stomach, and with afull glass of water. Patients should betold never to crush, chew, or break thetablet. The dose should never exceed 1tablet in a 24-hour time period.1Patients should be counseled to avoidother prescription and OTC medicationsthat contain ingredients similar tothose in Allegra-D 24 Hour. A myriad ofcough and cold or allergy-relief productsare available over the counter, andmany contain antihistamines or pseudoephedrine.Patients should beencouraged to read labels carefully andto ask questions when necessary.
Dr. Holmberg is a pharmacist with PhoenixChildren's Hospital, Phoenix, Ariz.
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