Dolasetron injection is used to prevent and treat nausea and vomiting that may occur after surgery. Dolasetron injection should not be used to prevent or treat nausea and vomiting in people receiving cancer chemotherapy medications. Dolasetron is in a class of medications called serotonin 5-HT₃ receptor antagonists. It works by blocking the action of serotonin, a natural substance that may cause nausea and vomiting.

Dolasetron injection comes as a solution (liquid) to be injected intravenously (into a vein) by a healthcare provider in a hospital or clinic. It is usually given as a single injection just before the end of surgery or as soon as nausea or vomiting occurs.

Dolasetron injection may be mixed in apple or apple-grape juice for children to take by mouth. It usually is given within 2 hours before surgery. This mixture may be kept at room temperature but must be used within 2 hours after mixing.

Before using dolasetron injection,

• tell your doctor and pharmacist if you are allergic to dolasetron, any other medications, or any of the ingredients in dolasetron injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: cimetidine; diuretics ('water pills'); fentanyl (Abstral, Actiq, Duragesic, Fentora, Lazanda, Onsolis, Subsys); lithium (Lithobid); medications to control blood pressure; medications for irregular heart beat such as atenolol (Tenormin, in Tenoretic); flecainide , quinidine (in Nuedexta), and verapamil (Calan, Covera-HS, Verelan, in Tarka); medications to treat migraines such as almotriptan (Axert), eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig); methylene blue; mirtazapine (Remeron); monoamine oxidase (MAO) inhibitors including isocarboxazid (Marplan), linezolid (Zyvox), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate); rifampin (Rifadin, Rimactane, in Rifamate, in Rifater); selective serotonin reuptake inhibitors (SSRIs) such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem, in Symbyax), fluvoxamine (Luvox), paroxetine (Brisdelle, Paxil, Pexeva), and sertraline (Zoloft); and tramadol (Conzip, Ultram, in Ultracet). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you or anyone in your family has or has ever had long QT syndrome (condition that increases the risk of developing an irregular heartbeat that may cause fainting or sudden death), or another type of irregular heart beat or heart rhythm problem, or if you have or have ever had low levels of potassium or magnesium in your blood, heart failure, or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

• dizziness
• fainting
• rapid, pounding, or irregular heart beat

Unless your doctor tells you otherwise, continue your normal diet.

Dolasetron injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• drowsiness
• chills

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or seek emergency medical treatment:

• hives
• rash
• itching
• difficulty breathing or swallowing
• changes in heart beat or heart rhythm
• dizziness lightheadedness, or fainting
• fast, slow or irregular heartbeat
• agitation
• confusion
• nausea, vomiting, or diarrhea
• loss of coordination
• stiff or twitching muscles
• seizures
• coma (loss of consciousness)

Dolasetron injection may cause other side effects. Call your doctor if you have any unusual problems while using 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 (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Anzemet® Injection