What is the Difference Between Cetirizine Hydrochloride and Cetirizine Dihydrochloride

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

Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec. Cetirizine 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 Cetirizine Dihydrochloride
4. Cetirizine Hydrochloride vs Cetirizine Dihydrochloride in Tabular Form
5. Summary – Cetirizine Hydrochloride vs Cetirizine Dihydrochloride

What is Cetirizine Hydrochloride?

Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec used 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.

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, including aggression and angioedema. Moreover, it is safe to use this medication during pregnancy, though it is not recommended to be used 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 Cetirizine Dihydrochloride?

Cetirizine 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, cetirizine dihydrochloride is less sedative compared to older antihistamines. It is taken orally.

Figure 02: The Chemical Structure of Cetirizine Dihydrochloride Compound

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

The bioavailability of cetirizine 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 Cetirizine Dihydrochloride?

Cetirizine hydrochloride and cetirizine dihydrochloride are important medications. Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec, while Cetirizine Dihydrochloride 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 cetirizine dihydrochloride is that cetirizine hydrochloride is useful in treating symptoms of hay fever and other upper respiratory allergies by relieving the symptoms temporarily, whereas cetirizine dihydrochloride is important in treating allergy symptoms that are associated with hay fever.

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

Summary – Cetirizine Hydrochloride vs Cetirizine Dihydrochloride

Cetirizine hydrochloride is a second-generation antihistamine that is sold under the name Zyrtec. Cetirizine Dihydrochloride 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 cetirizine dihydrochloride is that cetirizine hydrochloride is useful in treating symptoms of hay fever and other upper respiratory allergies by relieving the symptoms temporarily, whereas cetirizine dihydrochloride is important in treating allergy symptoms that are associated with hay fever.