Health Library Serotonin Antagonists (5-HT3 Receptor Antagonists)From Healthwise

Serotonin antagonists may be given as a pill or as a shot.

Serotonin antagonists work by blocking the effects of a chemical called serotonin, which is produced in the brain and the stomach.

Serotonin antagonists prevent and relieve nausea and vomiting caused by chemotherapy. They also are used before surgery to prevent nausea and vomiting caused by anesthesia. Serotonin antagonists also decrease episodes of bulimia in people with bulimia nervosa.

Serotonin antagonists prevent and relieve nausea and vomiting caused by chemotherapy and anesthesia. They are more effective when they are given with other medicines, such as dexamethasone (Hexadrol, for example) and aprepitant (Emend), if used for nausea or vomiting caused by chemotherapy.¹

Although serotonin antagonists cause fewer side effects than other antinausea medicines (antiemetics), side effects can include:

• Diarrhea or constipation.
• Dizziness and headache.
• Fatigue and sleepiness.
• Muscle cramps
• Nervousness.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

Serotonin antagonists are often used with other medicines, such as dexamethasone (Hexadrol, for example) and aprepitant (Emend), to prevent and control nausea and vomiting caused by chemotherapy.

These medicines should not be used by children who weigh less than 20 lb (9 kg) or are younger than age 3.

It is not known whether serotonin antagonists pass into breast milk. If you are breast-feeding, do not take these medicines without first talking to your doctor.

Although serotonin antagonists may be safe for use during pregnancy, do not take these medicines until you have discussed your pregnancy with your doctor.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

1. Berger AM, Clark-Snow RA (2005). Nausea and vomiting section of Adverse effects of treatment. In VT DeVita Jr et al., eds., Cancer: Principles and Practice of Oncology, 7th ed., pp. 2515–2523. Philadelphia: Lippincott Williams and Wilkins.

Author:	Kathe Gallagher, MSW	Last Updated: August 31, 2007
Medical Review:	Joy Melnikow, MD, MPH - Family Medicine Douglas A. Stewart, MD - Medical Oncology
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