API: Levocetirizine

What Is Levocetirizine and How Does It Work?

Levocetirizine dihydrochloride is a histamine H1-receptor antagonist derived from the second generation antihistamine cetirizine. The drug is an inverse agonist, which in turn prevents the release of other allergy chemicals that contribute to the histamine response—the drug does not actually cause mast cells to release histamine. Levocetirizine does not enter the brain or spinal cord in significant amounts, and therefore does not usually cause drowsiness in patients.

For more information, including a MSDS sheet, please see PNA’s Levocetirizine page.

Approved Indications1

  • Allergies: Levocetirizine is used for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 2 years and older, and for relief of symptoms associated with perennial allergic rhinitis in adults and children 6 months and older.
  • Chronic Idiopathic Urticaria: Levocetirizine is used for the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria in adults and children 6 months of age and older.

Side Effects and Drug Interactions

Common side effects in patients taking levocetirizine include2:

  • Drowsiness
  • Dry mouth
  • Nasal and throat irritation
  • Fatigue and weakness

Patients who suffer from severity of these common side effects should contact their pharmacist or physician right away. Patients who experience severe allergic, burning, numbness, or tingling, dark urine, painful urination, dizziness or fainting, irregular heartbeat, fever, hallucinations, mental or mood changes, thoughts of suicide, nosebleeds, seizures, shortness of breath, tremors, blurred vision, or jaundice should inform their physician immediately.

Patients with end-stage kidney disease or children younger than 12 years old with kidney disease should not take levocetirizine.3

Patients who have liver disease, kidney disease, or gallbladder problems should notify their physicians before taking levocetirizine. Children’s dosages should be followed precisely since a child’s body absorbs twice as much of the same drug dose as an adult’s body.

Patients who are allergic to levocetirizine or cetirizine should not take this drug.4 Ritonavir or theophylline may increase the risk of levocetirizine’s side effects

Cold or allergy medicine, sedatives, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression or anxiety can add to sleepiness caused by levocetirizine.

Latest News and Research

Antihistamines fall in different categories based on their properties and mechanism of action.5 First generation antihistamines were introduced in the late 1960s as a class of drugs that were inexpensive and widely available but which cross the blood-brain barrier and therefore caused drowsiness and decreased cognitive ability in patients. A second generation of antihistamines were developed in the 1980s, with more selective binding to H1 receptors. These drugs do not penetrate the blood-brain barrier and have a longer half-life than their predecessors. Third generation antihistamines, such as levocetirizine, actually belong to the second generation class but which are labeled as third generation because they derive from second-generation drugs.

Recent studies around optimizing the stability of levocetirizine show promise for the development of a fast-disintegrating preparation of the drug for more immediate effect in the body.6 Other researchers are looking into methods of delivering the drug as an oral film, which is associated with higher patient compliance due to convenience, especially in children, the elderly, and those who need a quick-acting solution to acute allergic symptoms.

Buying Guide

PNA is a recommended bulk supplier of Levocetirizine and other APIs. You can learn more about Levocetirizine here.

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Show 6 footnotes

  1. “LABEL: LEVOCETIRIZINE DIHYDROCHLORIDE- levocetirizine dihydrochloride solution,” December, 2014, http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2965ef46-18db-4615-9dce-bfb0f0b3366a
  2. “Levocetirizine,” December 1, 2015, http://www.drugs.com/cdi/levocetirizine.html
  3. “Xyzal,” http://www.rxlist.com/xyzal-drug/patient-images-side-effects.htm
  4. “Levocetirizine,” December 1, 2015,  http://www.drugs.com/pro/levocetirizine.html
  5. “Drug Class Review: Newer Antihistamines: Final Report Update 2,” 2010, http://www.ncbi.nlm.nih.gov/books/NBK50554/
  6. “FORMULATION AND IN-VITRO EVALUATION OF FAST DISINTEGRATING LEVOCETIRIZINE DIHYDROCHLORIDE TABLETS,” March/April 2015, http://jamonline.in/wp-content/uploads/2015/05/Formulation-And-In-vitro-Evaluation-Of-Fast-Disintegrating-Levocetirizine-Dihydrochloride-Tablets.pdf