fexofenadine (Allegra, Allegra Allergy 12 Hour, Allegra Allergy 24 Hour, Children's Allegra Allergy, Mucinex Allergy)
Classes: Antihistamines, 2nd Generation
Dosing and uses of Allegra (fexofenadine)
Adult dosage forms and strengths
tablets
- 30mg
- 60mg
- 180mg
oral suspension
- 30mg/5mL
oral disintegrating tablets
- 30mg
Seasonal Allergic Rhinitis/Chronic Idiopathic Urticaria
180 mg PO qDay or 60 mg PO BId
Dosing Modifications
Renal impairment (CrCl <80 mL/min): 60 mg PO qDay initially
Administration
Allegra ODT: Allow to disintegrate on tongue, followed by swallowing with or without water; take on empty stomach; do not chew
Coadministration with grapefruit, apple, or orange juice reduces bioavailability of fexofenadine by inhibiting P-gp; separate administration by at least 4 hr
Pediatric dosage forms and strengths
tablets
- 30mg
- 60mg
- 180mg
oral suspension
- 30mg/5mL
oral disintegrating tablets
- 30mg
Seasonal Allergic Rhinitis
<2 years: Use not recommended
2-12 years: 30 mg PO BId
>12 years: 60 mg PO BID OR 180 mg PO qDay
Allegra ODt
- 6-12 years: 30 mg PO BID
Chronic Idiopathic Urticaria
<6 months: Use not recommended
6 months-2 years: 15 mg PO BId
2-12 years: 30 mg PO BId
>12 years: 60 mg PO BID OR 180 mg PO qDay
Allegra ODt
- 6-12 years: 30 mg PO BID
Dosing Modifications
Renal impairment (CrCl <80mL/min)
- <6 months: Safety and efficacy not established
- 6 months to 2 years: 15 mg PO qDay, initially
- 2-12 years: 30 mg PO qDay, initially
- >12 years: 60 mg PO qDay, initially
Administration
Allegra ODT: Allow to disintegrate on tongue, followed by swallowing with or without water; take on empty stomach; do not chew
Coadministration with grapefruit, apple, or orange juice reduces bioavailability of fexofenadine by inhibiting P-gp; separate administration by at least 4 hr
Allegra (fexofenadine) adverse (side) effects
Varies in incidence and severity with the individual drug; also, individual patients vary in susceptibility
>10%
Vomiting (6-12%)
1-10%
Headache (5-10%)
Cough (4%)
Diarrhea (3-4%)
URTI (3%)
Back pain (2-3%)
Pyrexia (2%)
Dysmenorrhea (2%)
Dizziness (2%)
Stomach discomfort (2%)
Pain in extremity (2%)
Somnolence (1-3%)
Rhinorrhea (1-2%)
Postmarketing Reports
Sleep disorders (insomnia, paranoia)
Nervousness
Hypersensitivity reactions (anaphylaxis, urticaria, angioedema, chest tightness, dyspnea, flushing, pruritus, rash)
Warnings
Contraindications
Hypersensitivity
Cautions
Allegra ODT contains phenylalanine
Severe renal impairment
Coadministration with fruit juice may decrease efficacy
Pregnancy and lactation
Pregnancy category: C
Lactation: Excretion in milk unknown; use with caution (AAP states “compatible with nursing”)
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Allegra (fexofenadine)
Mechanism of action
H1 histamine receptor antagonist; competes for H1-receptor sites in target cells in the respiratory tract, blood vessels, and gastrointestinal tract; major metabolite of terfenadine
Absorption
Duration: ≥12 hr
Peak serum time: 2-3 hr (tablet); 2 hr (ODT); 1 hr (suspension)
Peak plasma concentration: 131 ng/mL
Distribution
Protein bound: 60-70%
Metabolism
Hepatic (5%)
Elimination
Half-life: 14.4 hr (31-72% longer in renal impairment)
Excretion: Feces (80%), urine (11%)
