Ondansetron acts by blocking the action of serotonin, a molecule present in the brain that can trigger nausea and vomiting.

 

What is Ondansetron?

Ondansetron is used to prevent nausea and vomiting associated with chemotherapy, radiation therapy or surgical procedures.

 

How should Ondansetron be taken?

Ondansetron can be taken orally in the form of tablets, soluble tablets or solutions. In general, the first dose is taken 30 minutes before chemotherapy, 1 or 2 hours before radiotherapy or one hour before surgical treatment. Sometimes, 1-3 doses per day may be administered during the whole period of chemo- or radiation therapy and for 1 or 2 days after the end of the treatment.

 

Side effects associated with Ondansetron

Possible side effects of Ondansetron include the following:

  • Constipation
  • Weakness
  • Fever
  • Headache
  • Drowsiness
  • Fatigue

 

It is important to see your doctor if the drug triggers:

  • Agitation
  • Hallucinations
  • Slowed, fast or irregular heartbeat
  • Dizziness, lightheadedness or fainting spells
  • Confusion
  • Convulsions
  • Difficulty breathing or difficulty swallowing
  • Chest pains
  • Fever
  • Shortness of breath
  • Swelling of eyes, face, lips, tongue, throat, hands, feet, ankles or calves
  • Stiff muscles or tics
  • Nausea, vomiting or diarrhea
  • Urticaria
  • Loss of coordination
  • Loss of consciousness
  • Vision problems
  • Itch
  • Rash
  • Excessive sweating

 

 

 

 

Contraindications and warnings associated with the use of Ondansetron

Before taking Ondansetron, it is important to inform your doctor:  

  • If you have any allergies to the active substance, its excipients or any other medication (especially if it is alosetron, dolasetron, or palonosetron, or granisetron)
  • If you are taking apomorphine
  • If you are taking any other medications, herbal remedies or supplements. Mentioning in particular: anticonvulsants, clarithromycin, erythromycin, fentanyl, lithium, anti-arrhythmic drugs, psychotropic drugs, drugs for migraine, methylene blue, mirtazapine, MAO inhibitors, moxifloxacin, SSRIs and tramadol
  • If you suffer (or have suffered or have a family member that has suffered) from long QT syndrome or other heart abnormalities, magnesium or potassium deficiency, heart failure or liver disease
  • If you are pregnant or breast-feeding
  • If you suffer from phenylketonuria