Who should not take Zofran?

While Zofran is generally well tolerated, and extremely helpful when experiencing nausea after starting a new medication, there are some drug interactions you’ll want to watch for.

Zofran is a serotonin receptor blocker—if serotonin receptors are blocked, there will be more serotonin circulating around your body. An increase in circulating serotonin can be dangerous because there are other medications that allow for increased serotonin in your body—medications that help with anxiety, depression (SSRI’s), migraine medications (Triptans), and antibiotics like Linezolid. If you are on one of the mentioned medications while taking Zofran, you may be putting yourself at risk for Serotonin Syndrome, a condition that occurs when your serotonin levels are dangerously high. This syndrome can have mild symptoms such as experiencing shakiness, trouble sleeping, excessive sweating. More extreme symptoms are high fever, uncontrollable diarrhea, and uncontrollable shaking and body movements. Of note, if any of those side effects are to occur while taking Zofran, please stop taking the medication and seek medical attention immediately.

Additionally, while cardiac side effects are definitely rare with Zofran, there are some reports of QT elongation when taking this medication, which is quite dangerous causing the heart to take longer to contract and relax. Who is at risk for this? Those who are taking antiarrhythmic medication, people with low potassium or magnesium levels, those who take antibiotics from the Fluroquinolone family (Ciprofloxacin, levaquin), or Macrolide family (Azithromycin).

If you have a history of the below mentioned conditions, you should speak to your medical provider before taking Zofran:

• Heart disease
• History of irregular heartbeat
• Liver disease
• Low levels of magnesium or potassium in the blood
• An unusual or allergic reaction to ondansetron, granisetron, other medications, foods, dyes, or preservatives
• Pregnant or trying to get pregnant
• Anxiety/depression and on SSRI’s
• History of PKU
• Breastfeeding