Let's take a minute to talk about your medication.  

This is Ondansetron, and you should take your dose as directed by your doctor.  

Ondansetron helps prevent and treat nausea and vomiting. You'll probably start feeling better in about 30 minutes, but it can take a little longer for full effects to occur.  

Ondansetron is usually well tolerated, but some side effects may occur, like headaches, fatigue, or constipation. These are normal and should go away. But, if these or other side effects become reasons you want to stop taking this medicine, please talk to your doctor or pharmacist.  

For best results, take Ondansetron as directed, and follow your doctor's advice for dietary changes that may also help you feel better.