image by: Joe Erlewein

HWN Suggests

Nauseating Evidence 1/3 (Ondansetron)

Cheap, safe, and usually effective makes this drug very popular. We commonly see this given in aliquots of 4 mg's. You can probably feel safe knowing that there has been no statistical difference noted in the dosing between 4 mg's and 8 mg's. "Yah, but one time.... blah blah blah." As you will see... the placebo of 0.9% saline improved symptoms in some patients. Self reporting can be very interesting...

Does ondansetron work for motion sickness? No... motion sickness is mostly driven by histamine. So the whole "let's give you some Zofran for the ride," probably has been more of a placebo effect. If you truly want to help with motion sickness, consider diphenhydramine. After all that…

read full article

Featured

 U.S. appeals court won't revive Zofran birth defect cases against GSK

The Boston-based 1st U.S. Circuit Court of Appeals ruled that federal law preempts the plaintiffs' state-law claims that GSK failed to warn doctors and pregnant women that animal studies found a link between birth defects and taking Zofran.

Articles of Interest

Antiemetic Use for Nausea and Vomiting in Adult Emergency Department Patients: Randomized Controlled Trial Comparing Ondansetron, Metoclopramide, and Placebo

In summary, this study found that although 20 mg intravenous metoclopramide and 4 mg intravenous ondansetron resulted in slightly greater VAS score reductions than saline solution placebo, differences did not reach significance.

Association of Maternal First-Trimester Ondansetron Use with Cardiac Malformations and Oral Clefts in Newborns

Ondansetron use in early pregnancy was not shown in this study to be associated with an increase in cardiac malformations or congenital malformations overall, however there may be a small increased association of oral clefts. IV ondansetron is therefore a safe option, when needed and this study should provide reassurance about ondansetron’s safety in the first trimester of pregnancy.

Do Ondansetron Prescriptions Reduce Pediatric Return Visits for Nausea and Vomiting?

An ondansetron prescription is associated with reduced 72-hour ED return visit rates for children with vomiting or acute gastroenteritis and is not associated with masking alternate diagnoses.

Most Drugs Aren't Tested on Pregnant Women. This Anti-nausea Cure Shows Why That's a Problem

For years, Zofran was the most popular morning-sickness medication in the U.S. Now it’s being accused of causing birth defects. The larger issue is a drug-safety system that excludes women from clinical trials, potentially putting them and their babies at risk.

Nausea Treatments – Droperidol vs Ondansetron RCT

Overall, droperidol and ondansetron had similar primary outcomes in acute nausea control. Patients needed fewer rescue/additional antiemetics in the droperidol group (16%) compared with the ondansetron group (37%); p = 0.016.

Off-label Use of Zofran: The Risks

There is an increasing number of lawsuits being filed over the off-label use of Zofran. The lawsuits come in the wake of recent studies and reports that Zofran may cause birth defects if taken during pregnancy. Originally, Zofran was created and intended as a powerful anti-nausea medicine for use by chemotherapy patients and surgery patients. The drug was never labeled by the manufacturer or the Federal Drug Administration to be used during pregnancy. And in fact, the manufacturer of the drug says that the active ingredient in Zofran is not recommended for pregnant women.

Ondansetron (Zofran) for Nausea and Vomiting in Pregnancy: Maybe Not for All Women

Obstetricians are in a difficult position here. While these data may raise some concerns, suggesting the possibility of a very small increase in absolute risk, many women experience severe nausea and vomiting which can interfere with functioning. Furthermore, early treatment of nausea and vomiting of pregnancy is recommended to prevent progression to hyperemesis gravidarum. From a mental health perspective, we also see that prolonged NVP, especially when severe, can lead to increased anxiety and depressive symptoms.

Ondansetron Pathway, Pharmacokinetics/Pharmacodynamics

Ondansetron is a first-generation serotonin (5-hydroxytryptamine or 5-HT) receptor antagonist which binds to the 5-HT3 receptor. It is a carbazole compound with carbon and nitrogen rings that give it a structural similarity to serotonin, allowing it to bind to the 5-HT3 receptor and exert its clinical effect.

Ondansetron-induced QT prolongation among various age groups: a systematic review and meta-analysis

This meta-analysis provides evidence that oral or intravenous administration of ondansetron, an antiemetic, may cause QT prolongation, especially in patients older than 18 years. There was no statistically significant effect of ondansetron in children younger than 18 years old, although caution must be exercised because cases have been reported in this age group as well. Therefore, we advise using ondansetron with caution, particularly in patients with a history of heart disease.

Rethinking Ondansetron as a First Line Agent for Nausea and Vomiting in the Setting of Abdominal Pain and Headache in the Emergency Department

Ondansetron was not superior to prochlorperazine for first-line use for N&V. Patients receiving prochlorperazine and not ondansetron, were least likely to need a second dose of antiemetics. Ondansetron was not superior to haloperidol as a second line antiemetic. Patients receiving haloperidol as a second antiemetic were least likely to need a third dose of antiemetics.

The Five Benefits of Zofran

No one in the history of the world has ever enjoyed the queasy, uncomfortable feeling of nausea. Unfortunately, nausea can strike for a variety of reasons, from post-operative tummy troubles to morning sickness or chemotherapy. One of the most common medications used to treat nausea is Zofran, known generically as ondansetron.

The History of Zofran

The only purposes for which the FDA has ever approved Zofran are 1) prevention of nausea and vomiting associated with initial and repeat courses cancer therapy, and 2) prevention of postoperative nausea and/or vomiting. GSK has never asked for or received FDA approval of Zofran for treatment of morning sickness in pregnant women.

Zofran 101: An Introduction to the Controversial Drug

The most prominent of these “off label” uses involved treating pregnant women with an extreme kind of morning sickness known as “Hyperemesis Gravidarum.” This condition typically presents early in the pregnancy, and it only happens in about one out of every one hundred pregnancies.

Zofran and Serotonin Syndrome

The drug is part of the antiemetic class, with selective 5-HTC3 receptor antagonist. Because the drug introduced additional serotonin into the body, users may experience serotonin syndrome.

Zofran for morning sickness: The risks are minimal

Original work suggested no increase in birth defects in women who took ondansetron early in pregnancy. However, more recent studies have raised concern over the possibility of a doubling in risk of cleft palate and heart defects in newborns exposed to ondansetron during pregnancy. It’s important to note that another study using similar information did not show the same increased risk for birth defects. Until we have better information about the true risks, ondansetron should be tried only after other therapies have failed.

Zofran: the must-have that's missing from your medicine cabinet

Have you ever experienced nausea, or even worse, vomiting, when starting a new medication? It’s an extremely common side effect of supplements, antibiotics, and hormonal treatments that can keep you from completing your full course of important medications! There’s one reliable treatment that nurses and doctors keep in their medicine cabinets to knock out nausea fast—Zofran. Here’s what you need to know.

Resources

Ondansetron (Zofran®, Zofran ODT®)

Ondansetron (Zofran®) is designed to block receptors in your body that control nausea and vomiting. These are called “serotonin type” (5-HT) receptors. 5-HT3 is a specific serotonin receptor that is located mostly in your brain, nervous system, and intestines (gut). When serotonin is released in the gut and brain, the body triggers vomiting. Ondansetron (Zofran®) binds to 5HT3 receptors instead of serotonin, and thereby stops the reflex to vomit.

StatPearls

Ondansetron is one of the medications most commonly used for the empiric treatment of nausea and vomiting. Ondansetron has excellent utility as an antiemetic drug, and it is effective against nausea and vomiting of various etiologies. Common uses of ondansetron include the prevention of chemotherapy-induced and radiation-induced nausea and vomiting, the prevention of postoperative nausea and vomiting, and off-label use for the prevention of nausea and vomiting associated with pregnancy. However, it is not effective for motion sickness-induced nausea.