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Medication Safety Issues
Sound-alike/look-alike issues:
Fexofenadine may be confused with fesoterodine
Allegra® may be confused with Viagra®
International issues:
Allegra® may be confused with Allegro® which is a brand name for frovatriptan in Germany; a brand name for fluticasone in Israel
Pronunciation
(feks oh FEN a deen)
U.S. Brand Names
Index Terms
Generic Available
Yes: Excludes orally disintegrating tablet and suspension
Canadian Brand Names
Pharmacologic Category
Pharmacologic Category Synonyms
Use: Labeled Indications
Relief of symptoms associated with seasonal allergic rhinitis; treatment of chronic idiopathic urticaria
Pregnancy Risk Factor
C
Pregnancy Considerations
Decreased fetal weight gain and survival were observed in animal studies. There are no adequate and well-controlled studies in pregnant women; use during pregnancy only if potential benefit to mother outweighs possible risk to fetus.
Lactation
Excretion in breast milk unknown/use caution (AAP rates “compatible”)
Contraindications
Hypersensitivity to fexofenadine or any component of the formulation
Warnings/Precautions
Disease-related concerns:
• Renal impairment: Use with caution in patients with renal impairment; dosage adjustment recommended.
Special populations:
• Pediatrics: Safety and efficacy have not been established in children <6 months of age; orally disintegrating tablet not recommended for use in children <6 years of age.
Dosage form specific issues:
• Orally disintegrating tablet: Contains phenylalanine.
Adverse Reactions
>10%:
Central nervous system: Headache (5% to 11%)
Gastrointestinal: Vomiting (children 6 months to 5 years: 4% to 12%)
1% to 10%:
Central nervous system: Fatigue (1% to 3%), somnolence (1% to 3%), dizziness (2%), fever (2%), pain (2%), drowsiness (1%)
Endocrine & metabolic: Dysmenorrhea (2%)
Gastrointestinal: Diarrhea (3% to 4%), nausea (2%), dyspepsia (1% to 2%)
Neuromuscular & skeletal: Myalgia (3%), back pain (2% to 3%), pain in extremities (2%)
Otic: Otitis media (2% to 4%)
Respiratory: Upper respiratory tract infection (3% to 4%), cough (2% to 4%), rhinorrhea (1% to 2%)
Miscellaneous: Viral infection (3%)
<1%, postmarketing, and/or case reports: Hypersensitivity reactions (anaphylaxis, angioedema, chest tightness, dyspnea, flushing, pruritus, rash, urticaria); insomnia, nervousness, paroniria, sleep disorders
Metabolism/Transport Effects
Substrate of CYP3A4 (minor); Inhibits CYP2D6 (weak)
Drug Interactions
Acetylcholinesterase Inhibitors (Central): Anticholinergics may diminish the therapeutic effect of Acetylcholinesterase Inhibitors (Central). Acetylcholinesterase Inhibitors (Central) may diminish the therapeutic effect of Anticholinergics. If the anticholinergic action is a side effect of the agent, the result may be beneficial. Risk C: Monitor therapy
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Risk C: Monitor therapy
Amphetamines: May diminish the sedative effect of Antihistamines. Risk C: Monitor therapy
Antacids: May decrease the serum concentration of Fexofenadine. Management: No specific recommendations concerning the time required between their administration are provided. Separate administration of each agent by as much time as possible to decrease the risk of an interaction. Exceptions: Calcium Carbonate; Magaldrate; Sodium Bicarbonate. Risk D: Consider therapy modification
Anticholinergics: May enhance the adverse/toxic effect of other Anticholinergics. Exceptions: Paliperidone. Risk C: Monitor therapy
Betahistine: Antihistamines may diminish the therapeutic effect of Betahistine. Risk C: Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Risk C: Monitor therapy
Eltrombopag: May increase the serum concentration of OATP1B1/SLCO1B1 Substrates. Management: According to eltrombopag prescribing information, consideration of a preventative dose reduction may be warranted. Risk D: Consider therapy modification
Erythromycin: May increase the serum concentration of Fexofenadine. Risk C: Monitor therapy
Grapefruit Juice: May decrease the serum concentration of Fexofenadine. Risk C: Monitor therapy
Itraconazole: May increase the serum concentration of Fexofenadine. Risk C: Monitor therapy
Ketoconazole: May increase the serum concentration of Fexofenadine. Risk C: Monitor therapy
P-Glycoprotein Inducers: May decrease the serum concentration of P-Glycoprotein Substrates. P-glycoprotein inducers may also further limit the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Risk C: Monitor therapy
P-Glycoprotein Inhibitors: May increase the serum concentration of P-Glycoprotein Substrates. P-glycoprotein inhibitors may also enhance the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Risk C: Monitor therapy
Pramlintide: May enhance the anticholinergic effect of Anticholinergics. These effects are specific to the GI tract. Risk D: Consider therapy modification
Rifampin: May decrease the serum concentration of Fexofenadine. Risk C: Monitor therapy
Verapamil: May increase the bioavailability of Fexofenadine. Risk C: Monitor therapy
Ethanol/Nutrition/Herb Interactions
Ethanol: Avoid ethanol (although limited with fexofenadine, may increase risk of sedation).
Food: Fruit juice (apple, grapefruit, orange) may decrease bioavailability of fexofenadine by ~36%.
Herb/Nutraceutical: St John's wort may decrease fexofenadine levels.
Storage
Store at controlled room temperature of 20°C to 25°C (68°F to 77°F). Protect from excessive moisture.
Mechanism of Action
Fexofenadine is an active metabolite of terfenadine and like terfenadine it competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels and respiratory tract; it appears that fexofenadine does not cross the blood brain barrier to any appreciable degree, resulting in a reduced potential for sedation
Pharmacodynamics/Kinetics
Onset of action: 60 minutes
Duration: Antihistaminic effect: ?12 hours
Protein binding: 60% to 70%, primarily albumin and alpha1-acid glycoprotein
Metabolism: Minimal (~5%)
Half-life elimination: 14.4 hours (31% to 72% longer in renal impairment)
Time to peak, serum: ODT: 2 hours (4 hours with high-fat meal); Tablet: ~2.6 hours; Suspension: ~1 hour
Excretion: Feces (~80%) and urine (~11%) as unchanged drug
Dosage
Oral:
Chronic idiopathic urticaria: Children 6 months to <2 years: 15 mg twice daily
Chronic idiopathic urticaria, seasonal allergic rhinitis:
Children 2-11 years: 30 mg twice daily
Children ?12 years and Adults: 60 mg twice daily or 180 mg once daily
Elderly: Starting dose: 60 mg once daily; adjust for renal impairment
Dosing adjustment in renal impairment: Clcr <80 mL/minute:
Children 6 months to <2 years: Initial: 15 mg once daily
Children 2-11 years: Initial: 30 mg once daily
Children ?12 years and Adults: Initial: 60 mg once daily
Administration: Oral
Suspension, tablet: Administer with water only; do not administer with fruit juices. Shake suspension well before use.
Orally disintegrating tablet: Take on an empty stomach. Do not remove from blister pack until administered. Using dry hands, place immediately on tongue. Tablet will dissolve within seconds, and may be swallowed with or without liquid. Do not split or chew.
Monitoring Parameters
Relief of symptoms
Dietary Considerations
Allegra® ODT 30 mg contains phenylalanine 5.3 mg/tablet.
Patient Education
Take as directed; do not exceed recommended dose. Store at room temperature in a dry place. If taking antacids, separate administration of antacid and this medication. Avoid use of other depressants, alcohol, or sleep-inducing medications unless approved by prescriber. You may experience mild drowsiness or dizziness (use caution when driving or engaging in tasks requiring alertness until response to drug is known); or nausea (small frequent meals, frequent mouth care, chewing gum, or sucking hard candy may help). Report persistent sedation or drowsiness, menstrual irregularities, or lack of improvement or worsening or condition. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to become pregnant. Consult prescriber if breast-feeding.
Geriatric Considerations
Plasma levels in the elderly are generally higher than those observed in other age groups. Once daily dosing is recommended when starting therapy in elderly patients or patients with decreased renal function.
Dental Health: Effects on Dental Treatment
No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
May cause drowsiness or dizziness
Mental Health: Effects on Psychiatric Treatment
None reported
Nursing: Physical Assessment/Monitoring
Assess effectiveness and interactions of other medications patient may be taking. Monitor effectiveness of therapy and adverse reactions at beginning of therapy and periodically with long-term use. Assess knowledge/teach patient appropriate use, interventions to reduce side effects, and adverse symptoms to report.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Suspension, oral, as hydrochloride:
Allegra®: 6 mg/mL (30 mL [DSC], 300 mL) [contains propylene glycol; raspberry cream]
Tablet, oral, as hydrochloride: 30 mg, 60 mg, 180 mg
Allegra®: 30 mg [DSC], 60 mg, 180 mg
Tablet, orally disintegrating, oral, as hydrochloride:
Allegra® ODT: 30 mg [contains phenylalanine 5.3 mg/tablet; orange cream flavor]
Pricing: U.S. (www.drugstore.com)
Suspension (Allegra)
30 mg/5 mL (300): $72.09
Tablet, orally-disintegrating (Allegra ODT)
30 mg (60): $115.49
Tablets (Allegra)
60 mg (60): $99.01
180 mg (30): $79.99
Tablets (Fexofenadine HCl)
30 mg (30): $19.99
60 mg (30): $38.99
180 mg (30): $61.99
References
“American Academy of Pediatrics Committee on Drugs. The Transfer of Drugs and Other Chemicals Into Human Milk,” Pediatrics, 2001, 108(3):776-89.
Day JH, et al, “Onset of Action, Efficacy and Safety of a Single Dose of 60 mg and 120 mg Fexofenadine HCl for Ragweed Allergy Using Controlled Antigen Exposure in an Environmental Exposure Unit,” J Allergy Clin Immunol, 1996, 97(1 Pt 3):1007.
“Fexofenadine,” Med Lett Drugs Ther, 1996, 38(986):95-6.
Simons FE, Bergman JN, Watson WT, et al, “The Clinical Pharmacology of Fexofenadine in Children,” J Allergy Clin Immunol, 1996, 98(6 Pt 1):1062-4.
International Brand Names
Lexi-Comp.com
Last full review/revision July 2009
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