Ondansetron Orally Disintegrating Tablets

Ondansetron is a prescription medication used to prevent and treat nausea and vomiting. It belongs to a class of drugs known as serotonin 5-HT$_3$ receptor antagonists, and is sold under various brand names, most notably Zofran.

Ondansetron works by blocking the action of serotonin in the body. When the body is exposed to certain substances or events (like chemotherapy, radiation, or surgery), it can release serotonin, a natural substance that stimulates a specific receptor (the 5-HT$_3$ receptor) in the gut and in the brain's "vomiting center" (the chemoreceptor trigger zone). This stimulation triggers the sensation of nausea and the subsequent act of vomiting. By blocking these receptors, ondansetron prevents the signals that cause nausea and vomiting from reaching the brain.

Ondansetron is FDA-approved for the prevention of nausea and vomiting associated with:

• Chemotherapy: It is very effective at preventing both immediate and delayed nausea and vomiting caused by cancer chemotherapy.

   

   

• Radiation therapy: It is also used to prevent nausea and vomiting from radiation treatment.

   

   

• Surgery: It is commonly administered to prevent and treat postoperative nausea and vomiting (PONV).

   

   

It is not typically effective for nausea caused by motion sickness.

Ondansetron is available in several oral forms, including:

• Standard tablets

   

   

• Orally disintegrating tablets (ODTs) that dissolve on the tongue

   

   

• Oral solution (liquid)

   

   

The dosage and timing of administration depend on the condition being treated. For example, for chemotherapy-induced nausea, the first dose is typically taken 30 minutes before the start of the treatment. For surgery, it's usually taken an hour before anesthesia.

Common side effects of ondansetron are generally mild and may include:

• Headache

   

   

• Constipation

   

   

• Weakness or fatigue

   

   

• Drowsiness