Zofran and Kidney Defects

There have been multiple reports of infants born with kidney defects after they were exposed to Zofran in the womb.

Overview

Zofran (ondansetron) is widely used “off-label” to treat nausea and vomiting in pregnant women during the first trimester. Unfortunately, the safety of Zofran for a fetus is not well-studied and most major birth defects occur in the first trimester.

Study Finds Zofran Increases Risk of Kidney Defects

Evidence linking Zofran and birth defects continues to grow. In 2013, a study linked Zofran with a 20% overall increased risk of birth defects. Researchers also found a 6-fold increased risk of kidney defects, described as “obstructive defects of renal pelvis and ureter,” but the estimate was based on small numbers and was imprecise.

Case Reports Link Zofran and Kidney Defects

Toronto Star published an investigative report linking Zofran and kidney defects in June 2014:

“At least 20 Canadian women treated with ondansetron for vomiting in pregnancy experienced serious suspected side-effects, including two infant deaths and multiple cases of newborns with heart defects and kidney malformations, according to a Star analysis of 2012 records.”

Although case reports alone do not prove that Zofran causes kidney defects, they underscore the lack of safety information. GlaxoSmithKline (GSK), the manufacturer of Zofran, has already agreed to settle allegations from the Justice Department of illegally marketing Zofran “off-label” in pregnant women.

What are Kidneys?

The kidneys are responsible for filtering blood and excreting toxins and wastes in urine. Most people are born with two kidneys, and each bean-shaped organ is located in the middle of the back below the rib cage.

Hydronephrosis

Hydronephrosis (which means “water in the kidneys”) is a common kidney defect that occurs when there is an obstruction in the ureter or urethra, which causes urine to back up into the kidneys. This causes swelling and distention of the kidneys. Without treatment, it can cause tissue damage, kidney failure, kidney stones, and infections.

Kidney Defects

Some of the most common kidney malformations include:

• Kidneys in the wrong place (ectopia)
• Kidneys in the wrong position (malrotation)
• Kidneys are joined together (horseshoe kidney)
• Missing kidneys (kidney agenesis)
• Cysts or fluid-filled secs inside the kidney (Polycystic Kidney Disease)
• Medullary sponge kidney (MSK)
• Metabolic diseases (cystinosis)
• And more