Ondansetron

Hypersensitivity reactions including anaphylaxis and bronchospasm may occur: discontinue therapy if suspected; monitor and treat promptly per standard of care until signs and symptoms resolve

Reduce dose with severe hepatic impairment

Use according to schedule, not PRN

Do not use instead of nasogastric suction

Ondansetron may mask progressive ileus or gastric distention in patients who are undergoing abdominal surgery or experiencing chemotherapy-induced nausea and vomiting; monitor for decreased bowel activity, particularly in patients with risk factors for gastrointestinal obstruction

Ondansetron is not a drug that stimulates gastric or intestinal peristalsis; should not be used instead of nasogastric suction

Serotonin syndrome reported with 5-HT3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs including SSRIs, SNRIs, MAO inhibitors, lithium, tramadol, methylene blue IV, and mirtazapine; if concomitant use with other serotonergic drugs is clinically warranted, patients should be made aware of potential increased risk for serotonin syndrome

Cross-sensitivity among selective serotonin antagonists may occur

Zofran ODT contains phenylalanine (caution for phenylketonurics)

Dose-dependent QT prolongation; avoid in patients with congenital long QT syndrome; ECG monitoring recommended in patients who have electrolyte abnormalities, CHF, or bradyarrhythmias or who are also receiving other medications that cause QT prolongation