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Zofran vs. Phenergan

Ondansetron (Zofran) is an antiemetic (or anti-nausea) medication. It's used to prevent nausea and vomiting after surgery or cancer treatments. It works by stopping a chemical called serotonin from binding to receptors in the brain that cause the feeling of nausea and vomiting. Ondansetron (Zofran) is taken by mouth, typically every 8 to 12 hours. It comes in different formulations, including orally disintegrating tablet (ODT) and oral solution. It can also be given as injection by a healthcare professional (HCP) in a hospital setting. Side effects of this medication include headache, tiredness, and constipation or diarrhea.

• Prevention of nausea and vomiting due to cancer medications (chemotherapy) or radiation therapy
• Prevention of nausea and vomiting after surgery

• Headache (up to 24%)
• Fatigue (up to 13%)
• Constipation (up to 9%)
• Diarrhea (up to 6%)

• Severe allergic reactions
• Life-threatening abnormal heart rhythm (QT prolongation)
• Serotonin syndrome
• Risk of heart attack
• Masking of gut blockage and stomach bloating
• Caution use in people with phenylketonuria (PKU) - orally disintegrating tablets only

Promethazine is a prescription medication with many uses, such as treatment or prevention of nausea, motion sickness, and allergy symptoms. Promethazine works by blocking several chemicals, including histamine, dopamine, and acetylcholine. It comes as tablets, an oral solution, rectal suppositories, and an injection. The dose of promethazine and how often you take it depends on your age and what medical condition you're taking it to treat. But it shouldn't be given to children younger than 2 years of age since it can cause serious breathing problems. Common side effects include sleepiness and dizziness.

• Runny nose, watery eyes, and other symptoms of allergies
• Runny or stuffy nose that isn't caused by allergies
• Rash, swelling, anaphylaxis, and other symptoms of an allergic reaction
• Dermographism
• Treatment or prevention of nausea and vomiting before and after surgery
• Treatment or prevention of motion sickness
• Treatment of pain along with other pain medications after surgery
• Help to relax your body and produce a light sleep, particularly before a procedure

• Feeling drowsy or tired
• Dizziness
• Confusion
• Dry mouth
• Nervousness
• Blurry vision

The following side effects are those additionally reported with promethazine injection at the injection site:

• Burning
• Pain
• Rash
• Swelling

• Potentially life-threatening slow breathing (respiratory depression)
• Serious tissue injury (Injection only)
• Excessive sleepiness
• Worsening of certain health problems
• Seizures
• Higher risk of infection (from low white blood cell count)
• Risk of serious nerve problems (neuroleptic malignant syndrome)
• Uncontrollable body movements