Generally speaking, taking ondansetron for nausea will eliminate all symptoms for about a quarter of patients. There is no way to know whether this drug will be effective for a certain patient without trying it, so doctors may prescribe ondansetron for nausea and then observe the patient to see if it works. This drug is commonly given to adults and to children as young as four and is almost always tolerated well, even if it doesn't completely eliminate nausea.
Studies indicate that ondansetron can completely prevent nausea in about 25% of patients who take the drug after surgery. A larger percentage of patients will feel some relief when taking ondansetron for nausea, though it is difficult to determine exactly how effective odnansetron is in these patients. It is not known whether there is a difference in how well ondansetron works in patients of different ages or genders.
In the treatment of nausea related to cancer treatment, ondansetron is considered to be quite effective. Though many patients will not experience complete relief from nausea, as many as 70% of patients, depending on the type of treatment, do experience a significant decrease in the nausea normally experienced. In most of these cases, patients may feel queasy or vomit a couple of times in a day, especially on the first day after treatment, though symptoms may improve considerably after the first 24 hours.
The best way to determine whether ondansetron will be an effective cure for nausea is for a patient to try taking the drug under the observation of a doctor. It is usually prescribed to patients who have recently undergone surgery or for patients who are currently undergoing cancer treatment, so most patients who try ondansetron for nausea will be able to be observed by a doctor. In some cases, the drug may take effect in about 6 hours, while in other cases it may take 24 hours or more to determine whether it will work. If ondansetron is not effective for a particular patient, other anti-nausea medications are available.
Not all patients will respond favorably when given ondansetron for nausea. There are a number of serious side effects that can occur with its use, including dizziness, headache, weakness, or drowsiness. This medication may also cause diarrhea or constipation. Occasionally, patients may have an allergic reaction to the drug. A doctor should be notified immediately if there are signs of this, such as shortness of breath, hives, or loss of consciousness.