What is the Difference Between Chlorpheniramine Maleate and Cetirizine Hydrochloride

The key difference between Chlorpheniramine maleate and Cetirizine hydrochloride is that Chlorpheniramine maleate is a first-generation antihistamine with a shorter duration of action, while Cetirizine hydrochloride is a second-generation antihistamine with a longer duration of action.

Chlorpheniramine maleate and Cetirizine hydrochloride are antihistamines that are primarily prescribed to treat allergies. These medications work by blocking the activity of histamine H1 receptors. Histamine H1 antagonists are generally used against allergic reactions, hay fever, rhinitis, urticaria, and asthma. Unlike other medications, both these medications are available over the counter. Chlorpheniramine maleate is a first-generation antihistamine, while cetirizine hydrochloride is a second-generation antihistamine. Therefore, cetirizine hydrochloride is less likely to cause drowsiness than chlorpheniramine maleate. The most common side effects of Chlorpheniramine maleate and Cetirizine hydrochloride include drowsiness, dry mouth, and headache. They can also cause other side effects, such as dizziness, fatigue, and upset stomach. Therefore, it is advisable to consult a healthcare professional regarding the risks and benefits of the medications before having them.

CONTENTS

1. Overview and Key Difference
2. What is Chlorpheniramine Maleate 
3. What is Cetirizine Hydrochloride
4. Similarities – Chlorpheniramine Maleate and Cetirizine Hydrochloride
5. Chlorpheniramine Maleate vs Cetirizine Hydrochloride in Tabular Form
6. Summary – Chlorpheniramine Maleate vs Cetirizine Hydrochloride

What is Chlorpheniramine Maleate?

Chlorpheniramine maleate is an antagonist of the Histamine-H1 receptor primarily prescribed to alleviate the symptoms associated with upper respiratory allergies such as rhinitis, urticaria, allergy, and common cold. The binding of Chlorpheniramine to the histamine H1 receptor blocks the action of endogenous histamines, temporally suspending its negative effects. The drug is primarily available in tablets, capsules, and liquid forms.

Chlorpheniramine maleate is an organic compound that belongs to the alkylamine class. It is absorbed well by the gastrointestinal tract after oral administration. Approximately 70% of the drug remains bound with plasma proteins during the distribution. Chlorpheniramine is primarily metabolized via cytochrome p450 in the liver and eliminated with an approximate half-life of 21-27 hours. The most common side effects of Chlorpheniramine maleate are drowsiness, dry mouth, blurred vision, and constipation.

What is Cetirizine Hydrochloride?

Cetirizine hydrochloride is a second-generation histamine H1 antagonist primarily prescribed to control allergic rhinitis and chronic urticaria. The main effect of Cetirizine hydrochloride is achieved through the selective inhibition of peripheral H1 receptors. It does not readily cross the blood-brain barrier, so no significant effect has been shown with the cerebral H1 receptors.

Cetirizine hydrochloride is absorbed well after oral administration as tablets or syrups with a maximum concentration within 1 hour. It has no proven food effect, while 93% of the absorbed drugs remain bound with plasma proteins. Cetirizine is partially metabolized in the liver and mainly excreted in the urine with a half-life of 8.3 hours. The most common side effects of cetirizine hydrochloride are drowsiness, dry mouth, and headache. It can also cause other side effects, such as dizziness, fatigue, and upset stomach.

What are the Similarities Between Chlorpheniramine Maleate and Cetirizine Hydrochloride?

• Chlorpheniramine maleate and Cetirizine hydrochloride are Histamine H-1 receptor antagonists.
• Both are primarily used to treat allergies.
• They are available over the counter.
• Both these drugs share common side effects such as drowsiness, dry mouth, and headache.
• They can interact with alcohol.

What is the Difference Between Chlorpheniramine Maleate and Cetirizine Hydrochloride?

Chlorpheniramine maleate and Cetirizine hydrochloride are antihistamines primarily prescribed against allergies. Both these medications are available over the counter. However, there is a distinct difference between Chlorpheniramine maleate and Cetirizine hydrochloride. Chlorpheniramine maleate is a first-generation antihistamine, while Cetirizine hydrochloride is a second-generation antihistamine. This means Cetirizine hydrochloride is less likely to cause drowsiness than Chlorpheniramine maleate. In addition, Chlorpheniramine maleate has a shorter duration of action than cetirizine hydrochloride, suggesting that Chlorpheniramine maleate needs to be taken more often. In addition to the common side effects such as drowsiness, dry mouth, and headache, Chlorpheniramine maleate is more likely to cause other side effects, such as blurred vision, constipation, and dizziness.

Below is a summary of the difference between Chlorpheniramine maleate and Cetirizine hydrochloride in tabular form for side-by-side comparison.

Summary – Chlorpheniramine Maleate vs. Cetirizine Hydrochloride

Chlorpheniramine maleate and Cetirizine hydrochloride are two Histamine-H1 antagonists primarily used to treat allergies. Chlorpheniramine maleate is a first-generation antihistamine with a shorter duration of action, while Cetirizine hydrochloride is a second-generation antihistamine with a longer duration of action. Chlorpheniramine maleate is more likely to cause side effects, such as blurred vision, constipation, and dizziness, and interact with alcohol and MAO inhibitors. Therefore, Cetirizine hydrochloride is generally a better choice for people looking for an antihistamine that is less likely to cause drowsiness. However, Chlorpheniramine maleate may be a better choice for people who need an antihistamine with a shorter duration of action. Ultimately, the best way to decide which antihistamine is to consult a healthcare professional. They analyze each medication’s risks and benefits and decide which is the best fit for individual needs.

Reference:

1. “Chlorpheniramine.” Uses, Interactions, Mechanism of Action | DrugBank Online.
2. Portnoy, Jay M, and Chitra Dinakar. “Review of CETIRIZINE Hydrochloride for the Treatment of Allergic Disorders.” Expert Opinion on Pharmacotherapy, vol. 5, no. 1, 2004, pp. 125–135.

Image Courtesy:

1. “Chlorphenamine” By Harbin – Own work (Public Domain) via Commons Wikimedia
2. “Cetirizine Structure” By User: Mysid – Own work Self-made in bkchem; edited in perl. (Public Domain) via Commons Wikimedia