This antihistamine is approved for the treatment of allergic rhinitis and chronic idiopathic uticaria in patients aged 6 and older.
Dr. Holmberg is a pharmacy resident
at the Carl T. Hayden Veterans Affairs
Medical Center in Phoenix, Arizona.
UCB Inc and sanofiaventis' Xyzal
Xyzal (levocetirizine dihydrochloride)
has received FDA approval for the
treatment of seasonal and perennial
allergic rhinitis and uncomplicated skin
manifestations of chronic idiopathic
urticaria. Xyzal is approved for use in
patients aged 6 and older; it offers a
once-daily dosing schedule and can be
taken without regard to meals.1
The American Academy of Allergy,
Asthma and Immunology estimates
that up to 40 million Americans are
affected by allergies. Seasonal allergic
rhinitis is the most common form of
allergic rhinitis and results from sensitivities
to seasonal pollen (trees, grass,
and weeds) and mold. Allergy symptoms
that last longer than 4 weeks and
are triggered by allergens, such as dust
mites, animal dander, and mold, are
characterized as perennial allergic
rhinitis. Chronic idiopathic urticaria is
defined as the presence of wheals and
itching that occurs daily or almost
daily, lasts for at least 6 weeks, and has
no known cause.2
Mechanism of Action
Xyzal is an antihistamine and the active
enantiomer of cetirizine. It exerts
its effect through inhibition of the H1
receptors.1
Clinical Trials
Safety data for Xyzal 5 mg daily were
determined by 12 randomized, placebo-controlled
trials in a total of 2549
patients with either seasonal or perennial
allergic rhinitis or chronic idiopathic
urticaria. Trials were considered
either short-term (duration of up to 6
weeks) or long-term (duration 4-6
months).1
FDA approval was based on 8 randomized,
placebo-controlled trials in
patients aged 12 and older using Xyzal
5 mg daily. Efficacy in the allergic rhinitis
study was assessed by a significant
improvement in symptoms, such as
sneezing, rhinorrhea, nasal pruritus,
and ocular pruritus, in the active treatment
group. When evaluated for efficacy
in patients with idiopathic urticaria,
symptoms, such as duration of pruritus
and wheal size and quantity, were
found to be significantly improved in
the Xyzal group.3
The recommended dose of 2.5 mg
for children was not evaluated by clinical
trials; instead, 2 short-term, placebo-controlled
clinical trials evaluated the
5-mg daily dose in a total of 243
patients aged 6 to 12.1 The recommended
dose is based on an extrapolation
of pharmacokinetics in adults and
children.4
Dosing
Xyzal is manufactured as a 5-mg
scored tablet. Because of its potentially
sedating effect, doses of Xyzal
should be administered in the evening.
Patients aged 12 and older are recommended
to use 5 mg once daily in the
evening; however, some patients may
experience symptom relief with a lesser
dose of 2.5 mg daily. Patients aged 6
to 11 should use 2.5 mg once daily in
the evening; 2.5 mg is the maximum
daily dose in this age group.
In patients aged 12 and older with
renal impairment, the dose of Xyzal
should be adjusted according to creatinine
clearance (CrCl) levels, as follows:
- CrCl 50 to 80 mL/min: 2.5 mg daily
- CrCl 30 to 50 mL/min: 2.5 mg every other day
- CrCl 10 to 30 mL/min: 2.5 mg twice weekly (every 3-4 days)1
Contraindications/Precautions
Xyzal is contraindicated in patients
with end-stage renal impairment as
defined by CrCl <10 mL/min or in
patients who are undergoing hemodialysis.
Patients aged 6 to 11 with
renal impairment should not use Xyzal.
Xyzal is contraindicated in patients
with a known hypersensitivity to any of
its components.
Patients are warned against using
Xyzal during any activity that requires
alertness, such as driving or operating
heavy machinery. Patients should not
use alcohol or other central nervous
system depressants while taking Xyzal.1
The most commonly reported adverse
effects in patients aged 12 and
older included somnolence, nasopharyngitis,
pharyngitis, fatigue, and
dry mouth. In patients aged 6 to 11, the
most common adverse events reported
were pyrexia, cough, somnolence,
and epistaxis.4
References
- Xyzal Complete Prescribing Information. products.sanofi-aventis.us/Xyzal/Xyzal.pdf. Accessed October 2007.
- New prescription allergy treatment Xyzal (levocetirizine dihydrocholid) now available for fall allergy season [press release]. www.sanofi-aventis.us/live/us/medias/BB8FA299-85FA-4101-89AA-CC108767BEAB.pdf. Accessed October 2007.
- Waknin Y. FDA Approvals: Xyzal, Perforomist, Factive. Medscape Medical News. www.medscape.com/viewarticle/558154. Accessed October 2007.
- Young D. New hay fever, hives treatment approved. Am J Health-Syst Pharm. 2007;64:1352.
