Ondansetron

Who should not use ondansetron?

Allergies to Ingredients. People who are allergic to any of the following should not take ondansetron. Your pharmacist can tell you all of the ingredients in the specific ondansetron products they stock.

Ondansetron should not be used while you are using certain other medicines. Before using ondansetron, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details

Do not take ondansetron unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share ondansetron with other people, even if they have the same condition as you. It may harm them.

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if ondansetron is right for you.

In particular, make sure that you discuss any of the following.

Tell your healthcare provider if you have any of the following.

• Long QT syndrome
• Electrolyte problems (such as low potassium or low magnesium)
• Congestive heart failure
• Other heart rhythm problems (slow heartbeat/bradycardia)

Tell your healthcare provider if you have had recent surgery on your gut (stomach or intestines).  In this case, as ondansetron prevents nausea and vomiting, it may be more difficult to determine if you are having complications from your surgery, such as any blockage, for example.

It is not known if or how ondansetron could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.

It is not known if ondansetron passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed.

Dosage

Usual Adult Dose of Ondansetron for Nausea/Vomiting — Chemotherapy Induced: Highly Emetogenic Cancer Chemotherapy (HEC):
-Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Usual Adult Dose of Ondansetron for Nausea/Vomiting: Highly Emetogenic Cancer Chemotherapy (HEC):
-Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Usual Adult Dose for Nausea/Vomiting–Radiation Induced: Recommended dose: 8 mg orally 3 times a day
-Total Body Irradiation: 8 mg orally 1 to 2 hours before each fraction of radiotherapy administered each day
-Single High-dose Fraction Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for 1 to 2 days after the completion of radiotherapy
-Daily Fractionated Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for each day radiotherapy is given