Ondansetron injection (patient information)

# Why is this medication prescribed
Ondansetron injection is used to prevent nausea and vomiting caused by cancer chemotherapy and surgery. Ondansetron is in a class of medications called 5-HT3 receptor antagonists. It works by blocking the action of serotonin, a natural substance that may cause nausea and vomiting.

# How should this medicine be used
Ondansetron comes as a solution (liquid) to be injected intravenously (into a vein) or into a muscle by a health care provider in a hospital or clinic. When ondansetron is used to prevent nausea and vomiting caused by chemotherapy, it is usually given 30 minutes before the start of chemotherapy. Additional doses may be given 4 hours after the first dose and 8 hours after the first dose. When ondansetron is used to prevent nausea and vomiting caused by surgery, it is usually given just before the surgery. Ondansetron is also sometimes given after surgery to patients who are experiencing nausea and vomiting and did not receive ondansetron before surgery.

# Other uses for this medicine
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

# What special precautions should I follow
Before taking ondansetron
- tell your doctor and pharmacist if you are allergic to ondansetron, alosetron (Lotronex), dolasetron (Anzemet), granisetron (Kytril), palonosetron (Aloxi), or any other medications.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nuritional supplements, and herbal products you are taking. Be sure to mention tramadol (Ultram, in Ultracet). Your doctor may need to change the doses of *your medications or monitor you more carefully for side effects.
- tell your doctor if you have or have ever had liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking ondansetron, call your doctor.

# What special dietary instructions should I follow
Unless your doctor tells you otherwise, continue your usual diet.

# Side effects

## Mild side effects
Ondansetron may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- headache
- constipation
- drowsiness
- feeling cold
- numbness, burning, or tingling in the fingers or toes
- fever
- pain, redness, swelling, warmth, or burning in the place where odansetron was injected

## Severe side effects
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
- rash
- hives
- itching
- swelling of the eyes, face, lips, tongue, throat, hands, feet, ankles, or lower legs
- hoarseness
- difficulty breathing or swallowing
- shortness of breath
- noisy, high pitched breathing
- blurred vision or vision loss
Ondansetron may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online  or by phone .

# What storage conditions are needed for this medicine
This medication will be stored in the hospital or clinic.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include:
- sudden loss of vision for a short time
- dizziness or lightheadedness
- fainting
- constipation
- irregular heartbeat

# What other information should I know
Keep all appointments with your doctor.

# Brand names
- Zofran Injection