What is the Difference Between Cetirizine Hydrochloride and Levocetirizine Dihydrochloride

January 2022 · 4 minute read

The key difference between cetirizine hydrochloride and levocetirizine dihydrochloride is that cetirizine hydrochloride is useful in treating symptoms of hay fever and other upper respiratory allergies by relieving the symptoms temporarily, whereas levocetirizine dihydrochloride is important in treating allergy symptoms that are associated with hay fever.

Cetirizine is a commonly used medication. Cetirizine hydrochloride and levocetirizine dihydrochloride are two major types of cetirizine medication. Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec. Levocetirizine dihydrochloride is a third-generation antihistamine medication used for treating allergic rhinitis and long-term hives of unclear cause.

CONTENTS

1. Overview and Key Difference
2. What is Cetirizine Hydrochloride 
3. What is Levocetirizine Dihydrochloride
4. Cetirizine Hydrochloride vs Levocetirizine Dihydrochloride in Tabular Form
5. Summary – Cetirizine Hydrochloride vs Levocetirizine Dihydrochloride 

What is Cetirizine Hydrochloride?

Cetirizine hydrochloride is a second-generation antihistamine sold under the name Zyrtec that is useful in treating allergic rhinitis, dermatitis, and urticaria. This medication is taken orally. Generally, the effects tend to begin within an hour and can last for about a day. The effects provided by cetirizine hydrochloride are similar to that of other antihistamines, including diphenhydramine.

Cetirizine Hydrochloride and Levocetirizine Dihydrochloride - Side by Side Comparison

Figure 01: The Chemical Structure of Cetirizine Hydrochloride

The most common side effects of cetirizine hydrochloride include sleepiness, dry mouth, headache, and abdominal pain. However, there can be some serious side effects as well, which include aggression and angioedema. Moreover, it appears to be safe for use during pregnancy, though it is not recommended for use during breastfeeding.

The bioavailability of cetirizine hydrochloride is about 70%, which indicates it is a well-absorbed medication. Its protein binding ability ranges between 88% to 96%. The metabolism of this medication is minimal, and the onset of action is around 20-42 minutes. The elimination half-life of cetirizine hydrochloride is about 6.5-10 hours. The duration of action of cetirizine hydrochloride is about 24 hours. Excretion occurs through urine and feces.

What is Levocetirizine Dihydrochloride?

Levocetirizine dihydrochloride is a third-generation antihistamine medication used for treating allergic rhinitis and long-term hives of unclear cause. This medication is sold under the trade name Xyzal. Specifically, levocetirizine Dihydrochloride is less sedative compared to older antihistamines. It is taken orally.

Cetirizine Hydrochloride vs Levocetirizine Dihydrochloride in Tabular Form

Figure 02: The Chemical Structure of Levocetirizine Dihydrochloride Compound

The most common side effects of this drug include sleepiness, dry mouth, cough, vomiting, and diarrhea. However, serious effects are rare. Moreover, it appears to be safe to use during pregnancy, but its effects during breastfeeding are unclear.

The bioavailability of levocetirizine dihydrochloride is very high, and its protein binding ability is also around 90%. The metabolism of this medication occurs in the liver, and the elimination half-life is around 6-10 hours. Excretion occurs in the kidney and fecal.

What is the Difference Between Cetirizine Hydrochloride and Levocetirizine Dihydrochloride?

Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec. Levocetirizine dihydrochloride, on the other hand, is a third-generation antihistamine medication used for treating allergic rhinitis and long-term hives of unclear cause. The key difference between cetirizine hydrochloride and levocetirizine dihydrochloride is that cetirizine hydrochloride is useful in treating symptoms of hay fever and other upper respiratory allergies by relieving the symptoms temporarily, whereas levocetirizine Dihydrochloride is important in treating allergy symptoms that are associated with hay fever.

The below infographic presents the differences between cetirizine hydrochloride and levocetirizine dihydrochloride in tabular form for side by side comparison.

Summary – Cetirizine Hydrochloride vs Levocetirizine Dihydrochloride

Cetirizine is a commonly used medication. Cetirizine hydrochloride and levocetirizine Dihydrochloride are two major types of cetirizine medication. The key difference between cetirizine hydrochloride and levocetirizine dihydrochloride is that cetirizine hydrochloride is useful in treating symptoms of hay fever and other upper respiratory allergies by relieving the symptoms temporarily, whereas levocetirizine dihydrochloride is important in treating allergy symptoms that are associated with hay fever.

Reference:

1. “Levocetirizine Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing.” WebMD.

Image Courtesy:

1. “Cetirizine structure” By User:Mysid – Own work Self-made in bkchem; edited in perl. (Public Domain) via Commons Wikimedia
2. “Levocetirizine structure 2” By Acdx – Own work based on: Levocetrizine Structural Formulae.png (CC BY-SA 3.0) via Commons Wikimedia

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