5-HT3 antagonist

5-HT3 antagonist

Introduction

5-HT3 antagonists, also known as serotonin receptor antagonists, are a class of medications that block the action of serotonin at the 5-HT3 receptor, a subtype of the 5-HT receptor family. These drugs are primarily used to prevent nausea and vomiting caused by cancer chemotherapy, radiation therapy, and surgery.

Mechanism of Action

5-HT3 antagonists work by inhibiting the 5-HT3 receptors located in the central and peripheral nervous systems. These receptors are ligand-gated ion channels that, when activated by serotonin, allow the flow of ions across the cell membrane, leading to neuronal depolarization and the transmission of signals that can trigger nausea and vomiting. By blocking these receptors, 5-HT3 antagonists prevent the initiation of these signals.

Clinical Uses

5-HT3 antagonists are primarily used in the management of:

• Chemotherapy-induced nausea and vomiting (CINV)
• Postoperative nausea and vomiting (PONV)
• Radiation-induced nausea and vomiting

These medications are often used in combination with other antiemetic agents to enhance their efficacy.

Common 5-HT3 Antagonists

Some of the commonly used 5-HT3 antagonists include:

• Ondansetron
• Granisetron
• Dolasetron
• Palonosetron

Side Effects

While 5-HT3 antagonists are generally well-tolerated, they can cause side effects such as:

• Headache
• Constipation
• Dizziness
• Fatigue

In rare cases, they may cause more serious side effects like QT interval prolongation, which can lead to cardiac arrhythmias.

Pharmacokinetics

The pharmacokinetic properties of 5-HT3 antagonists can vary, but they generally have a rapid onset of action and a duration of effect that can last from a few hours to several days, depending on the specific agent. For example, palonosetron has a longer half-life compared to other 5-HT3 antagonists, making it effective for delayed nausea and vomiting.

Related pages

• Serotonin receptor
• Antiemetic
• Chemotherapy
• Nausea

Gallery

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  Ondansetron structure

• Palonosetron structure

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• Image 2

• Image 3

• Image 4

5-HT3 antagonist

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  Ondansetron skeletal structure

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  Ondansetron skeletal structure

• Palonosetron structure

• 5-HT3 antagonist

• 5-HT3 antagonist

• 5-HT3 antagonist

• 5-HT3 antagonist