Understanding and controlling your respiratory allergies

Fexofenadine Hydrochloride

Pronunciation

Pronunciation: FEX-oh-FEN-a-deen HYE-droe-KLOR-ide
Class: Antihistamine

Trade Names

Allegra
- Tablets 60 mg
- Tablets 180 mg
- Oral suspension 30 mg per 5 mL (6 mg/mL)

Allegra
- ODT Tablets, orally disintegrating 30 mg

Fexofenadine Hydrochloride
- Tablets 30 mg
- Capsules 60 mg

Allegra 12 Hour (Canada)
Allegra 24 Hour (Canada)

Pharmacology

Competitively antagonizes histamine at the H 1 -receptor site.

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Pharmacokinetics

Absorption

T max is 2.6 h; C max is 131 ng/mL (tablets). T max is 2 h; C max is 88 ng/mL (orally disintegrating tablet [ODT]). T max is 1 h; C max is 118 ng/mL (suspension). Administration with a high-fat meal decreased AUC and C max by 21% and 20%, respectively (tablets), 40% and 60%, respectively (ODT), and 30% to 47%, respectively (suspension).

Distribution

60% to 70% is bound to plasma proteins. The drug does not cross the blood-brain barrier.

Metabolism

Approximately 5% is eliminated by hepatic metabolism.

Elimination

Mean t ½ is 14.4 h. Approximately 80% is excreted in the feces and 11% in the urine.

Onset

1 h.

Peak

2 to 3 h.

Duration

8 to 12 h.

Special Populations

Renal Function Impairment

Mild to moderate impairment with a CrCl of 41 to 80 mL/min has an 87% increase in C max and a 59% longer t ½ . Severe impairment with a CrCl of 11 to 40 mL/min has a 111% increase in C max and a 72% longer t ½ .

Hepatic Function Impairment

Pharmacokinetics in patients with hepatic impairment do not differ substantially from healthy subjects.

Elderly

C max is increased 99%.

Children

On average, oral Cl is 44% and 36% lower in children 6 to 12 and 2 to 5 yr of age compared with adults.

Indications and Usage

Symptomatic relief of symptoms associated with seasonal allergic rhinitis; treatment of uncomplicated skin manifestations of chronic idiopathic urticaria.

Contraindications

Standard considerations.

Dosage and Administration

Chronic Idiopathic Urticaria
Adults and children 12 yr of age and older

PO

Tablets

60 mg twice daily or 180 mg once daily.

Children 6 to 11 yr of age

PO

Tablets and ODT

30 mg twice daily.

Children 2 to 11 yr of age

PO

Oral suspension

30 mg (5 mL) twice daily.

Children 6 months to younger than 2 yr of age

PO

Oral suspension

15 mg (2.5 mL) twice daily.

Seasonal Allergic Rhinitis
Adults and children 12 yr of age and older

PO

Tablets

60 mg twice daily or 180 mg once daily.

Children 6 to 11 yr of age

PO

Tablets and ODT

30 mg twice daily.

Children 2 to 11 yr of age

PO

Oral suspension

30 mg (5 mL) twice daily.

Renal Function Impairment
Adults and children 12 yr of age and older

PO

Tablets

Start with 60 mg once daily.

Children 6 to 11 yr of age

PO

Tablets and ODT

Start with 30 mg once daily.

Children 2 to 11 yr of age

PO

Oral suspension

Start with 30 mg (5 mL) once daily.

Children 6 months to 11 yr of age

PO

Oral suspension

Start with 15 mg (2.5 mL) once daily.

General Advice

  • Administer without regard to meals. Administer with food if GI upset occurs.
  • Shake oral suspension well before each use.
  • Do not remove ODT from original blister package until time of use.
  • Instruct patients to dissolve ODT on the tongue, then swallow with or without water. ODT should not be chewed.

Storage/Stability

Store at controlled room temperature (68° to 77°F). Protect from excessive moisture.

Drug Interactions

Aluminum/Magnesium antacids

Taken concomitantly, fexofenadine AUC decreased 41%, and C max decreased 43%. Separate administration times.

Erythromycin and ketoconazole

Increased plasma levels of fexofenadine.

Fruit juices (eg, apple, grapefruit, orange)

May reduce fexofenadine plasma levels.

Adverse Reactions

CNS

Headache (11%); dizziness, drowsiness, somnolence/fatigue (1%); insomnia, nervousness, sleep disorders (postmarketing).

EENT

Nasopharyngitis, otitis media, rhinorrhea (2%).

GI

Vomiting (6%); dyspepsia (5%); diarrhea (3%); nausea, stomach discomfort (2%).

Genitourinary

Dysmenorrhea (2%).

Musculoskeletal

Back pain, myalgia (3%); pain in extremity (2%).

Respiratory

Cough, upper respiratory tract infection (4%).

Miscellaneous

Accidental injury, viral infection, including cold and flu (3%); fever, pain (2%); hypersensitivity, including anaphylaxis, angioedema, chest tightness, dyspnea, flushing, pruritus, rash, urticaria (postmarketing).

Precautions

Monitor

Assess patient for allergy symptoms before starting therapy and periodically throughout therapy.


Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 6 mo of age.

Elderly

Use with caution because elderly patients are more likely to have decreased renal function.

Hypersensitivity

Rare cases of hypersensitivity reactions with manifestations such as angioedema, chest tightness, dyspnea, flushing, and systemic anaphylaxis have been reported.

Renal Function

Use lower starting dose.

Phenylketonurics

Each 30 mg ODT contains phenylalanine 5.3 mg, a component of aspartame.

Overdosage

Symptoms

Dizziness, drowsiness, dry mouth.

Patient Information

  • Advise patient to take without regard to meals but to take with food if stomach upset occurs.
  • Advise patient that if allergy symptoms are not controlled not to increase the dose of medication or frequency of use but to inform health care provider.
  • Inform patient that larger doses or more frequent dosing does not increase effectiveness and may cause drowsiness.
  • Caution patient not to take any OTC antihistamines while taking this medication unless advised by health care provider.
  • Caution patient to avoid alcohol and other CNS depressants (eg, sedatives) while using this medication.
  • If patient is to have allergy skin testing, advise not to take the medication for at least 4 days before the skin testing.
  • Caution patient that drug may cause drowsiness and to use caution driving or performing other tasks requiring mental alertness until tolerance is determined.
  • Instruct patient to stop taking drug and report any symptoms of persistent dizziness or excessive drowsiness to health care provider.
  • Instruct patients to shake oral suspension well before each use.
  • Instruct patients not to remove ODT from original blister package until time of use.
  • Instruct patients to dissolve ODT on the tongue, then to swallow with or without water and not to chew the ODT.

Copyright © 2009 Wolters Kluwer Health.

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