Zofran, or ondansetron, is an anti-nausea medication known as an antiemetic. It can be prescribed under the brand names Zofran, Zofran ODT and Zuplenz. It works by blocking the chemicals that trigger nausea and vomiting and is most often used after surgeries, along with cancer treatments and to treat vomiting associated with pregnancy. It is extremely effective, but also extremely expensive.
Prescription Medication Facts Zofran
Zofran belongs to the anti-emetic class of drugs which are useful for preventing and controlling nausea, but achieves this through a mechanism which is different to most other common anti-emetics on the market. Because of this difference, it can be prescribed for nausea where other older anti-emetics would normally be contraindicated.
The drug functions by indirectly reducing the activity of the vagus nerve in the brain. That particular nerve located in the medulla oblongata is the “vomiting center.” Zofran also blocks serotonin uptake in the chemoreceptor trigger zone, which communicates with the vomiting center. The drug does not work to curb the effects of motion sickness-related nausea because that form of nausea is caused by dopamine and the muscarinic receptors instead.
Zofran is most often administered intravenously about half an hour before chemotherapy or radiation in cancer patients. For post-operative nausea and vomiting it can be taken orally. It also sometimes helps with acute cases of gastritis and is occasionally used off-label to treat cyclic vomiting syndrome. The most common off-label use is to treat vomiting in pregnant women and also hyperemesis gravidarum. Its safety for use by pregnant women is questionable. Some studies have indicated increased risk of clef palate in babies, but other studies have indicated no risks.
Uses of Zofran
Older varieties of anti-emetics consist of tranquilizers and first generation antihistamines, which work by antagonizing dopamine receptors in the central nervous system. This can aggravate the symptoms of illnesses such as Parkinson’s disease and hyperprolactinemia, so not every patient is an ideal candidate for treatment with these types of anti-nausea medications.
Zofran relieves nausea by antagonizing 5-HT3 receptors instead of dopamine receptors. The 5-HT3 receptor is a kind of serotonin receptor present in the central nervous system that is involved in transmitting signals of nausea and controlling peristalsis of the intestines. There are a significant amount of these receptors in the digestive tract, and this makes Zofran very effective for nausea that occurs after eating or due to stomach issues.
Zofran is highly regarded for the treatment of nausea due to chemotherapy and radiation therapies. Cancer treatment generally leaves patients feeling fatigued, and unlike other anti-emetics, Zofran doesn’t cause any appreciable sedation so it doesn’t compound the fatigue experienced during chemotherapy. It is also recommended for nausea following surgical procedures.
The medication may be a potential treatment for schizophrenia as well. When it is coupled with the common schizophrenia drug, haloperidol, there is a significant improvement in negative symptoms. The drugs in combination also lessen the common negative side effects of haloperidol. It also may potentially be a treatment for the psychosis associated with Parkinson’s disease, but scientists are unsure how this works because zofran does not interact with dopamine and dopamine is associated largely with psychosis. It may also help with obsessive compulsive disorders (OCD), but extensive research has not been conducted. Sometimes it is used to treat irritable bowel syndrome (IBS), which is also controlled by the enteric nervous system. The same mechanisms controlling vomiting are also associated with colon contractions. Postanesthetic shivering also appears to be lessened by Zofran.
Dosage of Zofran
Zofran tablets are available in strengths of either four mgs or eight mgs. The particular dosage will be based around a patient’s condition, response to the drug, and the prescribing doctor’s recommendation. Zofran has a long duration of effect and can be administered once daily to control chronic nausea, or up to three times per day to treat the nausea caused by cancer treatments.
As tablets can be hard to swallow and keep down for sufferers of nausea who are vomiting frequently, the medication is also available in the form of sublingual wafers. These are soluble tablets that are placed under the tongue allowing the medication to absorb into systemic circulation through the veins in the mouth. A liquid suspension of Zofran is available in a 4 mgs per 5 mls strength.
Side effects of Zofran
The side effects of Zofran are very mild compared to anti-emetics that target dopamine receptors. These types of anti-emetics can lead to withdrawal psychosis, pseudoparkinsonism, and a life threatening condition called neuroleptic malignant syndrome. The side effects of Zofran however, are rarely serious and include headaches, vertigo and constipation.
Patients with a congenital heart defect called long QT syndrome may not be able to take Zofran due to the drug having a potential to increase the QT interval prolongation when administered to these patients. In this case, doctors will often recommend a lower does than is usually given if Zofran is the best choice for the patient. Otherwise, dopamine antagonists would be the preferred treatment.
Allergies can occur in response to Zofran, and are characterized by the usual side effects attributed to a drug allergy. These side effects include hives, trouble breathing, swelling, and vision problems. In the case of an allergy, the medication should be stopped and the patient should be examined by a medical professional. A serious reaction like anaphylaxis may occur rarely as with any allergy.
Like other prescription medication, Zofran is used only under the recommendation of a qualified doctor who can tailor its usage and dose to the patient’s needs. Whether or not a person can use Zofran will be based on the source of their nausea, any present allergies, and the price of the medication.