What is Ondansetron? Uses, effects, side effects & warnings

What is Ondansetron?

Ondansetron inhibits the action of the body's chemicals that trigger nausea and vomiting. Ondansetron is used to stop nausea and vomiting which could result from treatment for cancer, surgery, chemotherapy, and radiation treatment. Ondansetron can be used for reasons that are not mentioned in this guideline.

Warnings

It is not recommended to use ondansetron when you are also taking apomorphine (Apokyn). Ondansetron should not be used in the event that you have an allergy to it or similar medicines like dolasetron (Anzemet) and granisetron (Kytril), as well as palonosetron (Aloxi). Before you take ondansetron, inform your doctor whether you suffer from liver disease or have a family or personal background for Long QT syndrome.

Orally disintegrating tablets of Ondansetron may contain phenylalanine. Inform your physician if you suffer from the condition known as phenylketonuria (PKU). Ondansetron can cause serious side effects. These include blurred vision, temporary loss of vision (lasting from one or two minutes to several hours), a slow heart rate, difficulty breathing, anxiety, agitation, experiencing shivering, feeling as if you'll pass out, and having less frequent urination or none at all. Take this medicine off your list and contact your doctor immediately if you experience any of these symptoms. Ondansetron could affect your ability to think or react. Be mindful when driving or carrying out activities which necessitate your constant vigilance, such as performing essential services.

Before taking ondansetron

It is not recommended to make use of ondansetron when:

You are also taking the drug apomorphine (Apokyn) as well as
You are allergic to ondansetron and similar medicines (dolasetron and granisetron, as well as palonosetron).

To ensure that ondansetron is suitable for you, inform your doctor if you suffer from:

Liver disease;
An electrolyte imbalance (such as low concentrations of magnesium, potassium, or magnesium in the blood);
Congestive heart insufficiency, slow heartbeats;
A family or personal background of QT syndrome or
A blockage inside the digestion tract (stomach or the intestines)

Ondansetron should not be intended to harm an unborn baby. Consult your physician if you are expecting. It's not clear if ondansetron is absorbed into breast milk or whether it can harm the nursing infant. Inform your doctor if you are breastfeeding a baby. Ondansetron is not a drug that has been approved for use by children younger than 4 years of age. Orally disintegrating tablets of Ondansetron could contain phenylalanine. Consult your doctor if you suffer from phenylketonuria (PKU).

How to take Ondansetron?

Consume ondansetron exactly as directed by your physician. Follow the directions on the prescription label. Don't take this medication in greater or lesser doses or for longer than the recommended time. Ondansetron can be taken either with or without meals. The first doses are normally given prior to the commencement of your chemotherapy or radiation treatment. Follow the dosing guidelines of your physician with care. You can take the Ondansetron standard tablet with a cup of water. To take the oral tablets that disintegrate (Zofran ODT):

Place the tablet in the blister pack until you're ready to take it. Then, open the box and peel off the foil. Don't push a tablet into the foil, or you could cause damage to the tablet.
Make use of dry hands to take off the tablet, then put it into your mouth.
Don't swallow the tablet completely. Let it dissolve in your mouth without chewing.
Take a few sips as the tablet disintegrates.

To use ondansetron oral soluble film (strip) (Zuplenz):

Place this strip within the pouch made of foil until you're ready to apply the medication.
With clean hands, take off the strip from your hands and put the strip on top of your tongue. It will begin to break down in a matter of minutes.
Don't swallow the entire strip. Let it dissolve into your mouth without chewing.
Take a few breaths after the strip has disintegrated. If you wish, take a drink to assist in swallowing the strip that has disintegrated.
Wash your hands after you have used Zuplenz

Take measurements of liquid medicines using the dosing syringe that comes with it or using a specially designed measuring spoon or a medicine cup. If you don't have a device for measuring doses, you can ask your pharmacist for one.

Place it in a cool, dry place free of heat, moisture, and light. Keep liquid medication in an upright place.

What happens if I miss the dose?

Do the dose you missed as quickly as you can remember. Avoid any missed doses if you are close to the time of the next dose. Don't take any extra medication to make up for the missed dose.

What happens if I overdose?

For medical emergencies, seek emergency medical attention or contact the Poison Help Line toll-free at 1-800-222-1222.

The symptoms of an overdose can consist of sudden loss of vision or severe constipation, feeling lightheaded, or fainting.

What should be avoided?

Ondansetron could affect your ability to think or react. Be cautious when you drive or perform things that require you to be vigilant.

Side effects of Ondansetron

Take immediate medical care. If you show symptoms warnings of an allergy reaction, the ondansetron:difficuhives,, rash, hives and fever; chills, breathing difficulties or swelling of your lips, face, and throat.

Contact your doctor immediately. If you are suffering from:

Constipation that is severe and stomach pains, as well as excessive bloating;
Headache, chest pain, fainting, extreme dizziness, and fast heartbeats;
Heartbeats that are fast or rapid
Jaundice (yellowing of the eyes or skin);
Blurred vision, or temporary vision loss (lasting between one or two minutes and more than a few hours);
Serotonin levels that are high in the body cause hallucinations, agitation, and fever. They also experience a rapid heart rate and hyperactive reflexes. Nausea, vomiting, diarrhea, loss of coordination, and fainting.

Common side effects from ondansetron include:

Constipation or diarrhea
Headache
Sleepiness or
Fatigued feeling.

This is not a comprehensive list of possible side effects, and other side effects could occur. Contact your doctor for advice regarding medical adverse effects. You can report symptoms to the FDA at 1-800-FDA-1088.

Details on dosage

Usual Adult Dose of Ondansetron for Nausea/Vomiting—Chemotherapy Induced:

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):
Recommended dose: 24 mg taken orally 30 minutes prior to the beginning of single-day HEC (including doses that are 50 mg/m2 and higher).

Moderately Emetogenic Cancer Chemotherapy (MEC):
Dosage recommended 8 mg, twice daily, with the first dose being administered 30 minutes prior to the commencement of chemotherapy and the second dose eight hours later, followed by 8 mg taken daily, orally, 2 times (every twelve hours) for a period of 1 to 2 days following the conclusion of chemotherapy.

Parenteral:
Recommended dose: 0.15 mg/kg IV. This is followed by one dosage (infused for 15 minutes) 30 minutes prior to the beginning of chemotherapy emetogenic, and then the doses to follow between 4 and 8 hours following the initial dose.
Maximum dose: 16 mg per dose

Comments:
Multi-day, single-dose administration of 24 mg taken orally to treat HEC is not yet studied.
The injection solution is to be diluted prior to the administration of the IV.

Uses:
Prevention of vomiting and nausea caused by HEC or MEC
Prevention of vomiting and nausea that are associated with repeat and initial treatments of emetogenic chemotherapy

Usual Adult Dose of Ondansetron for Nausea or Vomiting:

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):
Recommended dose: 24 mg taken orally 30 minutes prior to the beginning of single-day HEC (including doses that are 50 mg/m2 and higher).

Moderately Emetogenic Cancer Chemotherapy (MEC):
The recommended dose is 8 mg, every day, twice per day. the first dose being administered 30 minutes prior to the commencement of chemotherapy. The second dose was given 8 hours later, and then 8 mg daily, orally, 2 times (every twelve hours) for a period of 1 to 2 days following the conclusion of chemotherapy.

Parenteral:
The recommended dose is 0.15 mg/kg IV. Take the initial dosage (infused in 15 minutes) 30 minutes prior to the beginning of chemotherapy emetogenic and the subsequent doses administered 4 to 8 hours after the initial dose.
Maximum dose: 16 mg per dose

Comments:
Multi-day, single-dose administration of 24 mg daily for HEC is not yet studied.
The injection solution is to be diluted prior to the administration of the IV.

Uses:
Prevention of vomiting and nausea that are caused by HEC or MEC
Preventing nausea and vomiting that are associated with repeat and initial treatments of emetogenic chemotherapy

Usual Adult Dose of Ondansetron for Nausea/Vomiting—Postoperative:

Oral:
Recommended dose: 16 mg orally for 1 hour prior to the induction of anesthesia.

Parenteral:
Recommended dose: 4 mg in IV (undiluted) prior to the induction of anesthesia or postoperatively (nausea or vomiting for 2 hours after surgery).
Alternate route: 4 mg IM (undiluted)

Comment:
The administration of a second dose will not give additional control over vomiting and nausea.

Use:
Preventing postoperative nausea and vomiting

Usual Adult Dose for Nausea/Vomiting--Radiation Induced:

Dosage recommended: 8 mg taken orally three times per day.
Total Body Irradiation (TBI): 8 mg taken orally, one up to 2 hours prior to each portion of radiotherapy that is given each day.
Single high-dose fraction Radiotherapy to the abdominal area: 8 mg taken orally 1–2 hours prior to radiotherapy, and subsequent doses every 8 hours after the first dose for up to 2 days following the conclusion of radiotherapy.
Daily Fractionated Radiotherapy for the abdomen: 8 mg taken orally one to two hours prior to radiotherapy, with doses every 8 hours following the initial dose for each day when radiotherapy is offered.

Use:
Prevention of vomiting and nausea that are associated with radiotherapy, whether as a result of complete body irradiation, one high-dose fraction, or daily fractions of radiation to the abdomen

Usual Pediatric Dose for Nausea/Vomiting—Postoperative:

Parenteral:
One month up to twelve years old:
less than 40 kilos:
Recommended dosage: 0.1 mg/kg IV over 2–5 minutes immediately after or prior to anesthesia induction postoperatively (nausea or vomiting that occurs within a few minutes of surgery).

40 kilos and above:
The recommended dose is 4 mg IV in 2 to 5 minutes following anesthesia induction or postoperatively (nausea and/or vomiting that may occur within a few minutes of surgery).

Use:
Prevention of nausea postoperatively and vomiting

Usual Pediatric Dose for Nausea/Vomiting—Chemotherapy Induced:

Oral:
Between 4 and 11 years:
Recommended dose: 4 mg orally, 3 times a day. the first dose given 30 minutes prior to the beginning of chemotherapy. Then, follow-up doses are given every 4 or 8 hours following the initial dose. Then, 3 doses of 4 mg orally each per day (every eight hours) for up to 2 days following the end of chemotherapy

12-year-olds and older:
The recommended dose is 8 mg every day, twice per day. the first dose given 30 minutes prior to the commencement of chemotherapy, and the second dose eight hours later, followed by 8 mg taken orally twice a day (every 24 hours) for up to 2 days following the end of chemotherapy.

Parenteral:
6 months to 18 years old:
The recommended dose is 0.15 mg/kg IV. This is followed by the initial dosage (infused in 15 minutes) 30 minutes prior to the beginning of chemotherapy with emetogenic agents, and then the following doses given within 4 to 8 hours of the first dose.
Maximum dose: 16 mg (per dose)

Comments:
The formulation for injection is to be diluted in 50 mL prior to administration.
The drug should be used to stop vomiting and nausea caused by moderately to extremely emetogenic chemotherapy.

Uses:
Prevention of vomiting and nausea that are associated with moderately emetogenic chemotherapy
Preventing vomiting and nausea that can be caused by the first and repeated treatments of emetogenic chemotherapy

Interaction with other drug

Ondansetron can trigger a grave heart condition, especially when you take certain medications simultaneously that include antidepressants, antibiotics, heart rhythm medicines, antipsychotic drugs, and medications for treating malaria, cancer, HIV, or AIDS. Discuss with your doctor the medicines you take as well as the medicines you take or stop taking during the treatment you receive with ondansetron.

Ondansetron that you take while using other medicines could cause excessive levels of serotonin to accumulate within your body. This is an issue known as "serotonin syndrome," which could be fatal. Consult your physician if you also take:

Medication to treat depression;
Medication to treat the symptoms of a mental disorder;
A drug called a narcotic (opioid) medication or
Medication to stop nausea or vomiting.

This isn't a complete list, and a variety of other medications can interfere with ondansetron. This includes over-the-counter and prescription medications, vitamins, and herbal remedies. Make a list of all the medicines you take for any doctor who will treat you.