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20 May 2015

Did Zofran Cause These 5 Heart Defects?

Five epidemiological studies have now found an association between the anti-nausea drug Zofran and major birth defects. In two early studies, researchers linked Zofran’s active ingredient to increased risks of cleft palate and kidney defects, as well as a 20% rise in the rate of birth defects overall.

But more recently, no less than three large-scale studies have found an association between Zofran and congenital heart defectspulse rate

At least seven US families have filed lawsuits against GlaxoSmithKline, Zofran’s manufacturer, and serious allegations continue to mount, including claims that the drug company has been aware of Zofran’s possible risks for years but has failed to warn the public.

In line with the medical community’s current research on Zofran and pregnancy, the majority of these complaints seek damages for congenital heart defects (CHD). To date, five families have alleged that prenatal exposure to Zofran caused their children to develop CHDs.

In this article, we’ll describe the five specific heart defects that have been named in these lawsuits.

Lawsuits Claim Anti-Nausea Drug Caused These 5 Congenital Heart Defects

On February 16, 2015, a mother from Massachusetts filed the nation’s second Zofran birth defect lawsuit. Her complaint was registered under case number 1:15-cv-10429 in the United States District Court of the District of Massachusetts.

After taking Zofran as an “off label” morning sickness treatment during early pregnancy, the plaintiff claims that her daughter was born with three congenital heart defects:

  • Atrial septal defect
  • Right ventricular hypertension
  • Aortic arch hypoplasia

1. Atrial Septal Defect

In healthy human hearts, the organ’s uppermost chambers are separated by a complete barrier, or septum. The septum fully separates these chambers, maintaining blood pressure. A complete septum also prevents oxygen-rich blood on one of the side of the heart from mixing with oxygen-poor blood on the other side.

An atrial septal defect is a hole in this barrier, a perforation between the heart’s top chambers, or atrium.

Atrial septal defects can lead to numerous serious complications later in life. Since oxygen-rich blood is allowed to blend with oxygen-poor blood, the heart is forced to work extremely hard to nourish the body’s other organs with the nutrients they need. Potentially life-threatening complications, including heart failure and stroke, are possible.

In this case, plaintiff says that her daughter has been forced to undergo “thirteen different surgeries” to repair her congenital defects.

Surgical intervention is not an uncommon treatment option for atrial septal defects. In the most frequent procedure, a catheter is inserted through a vein in a child’s groin, pushed up to the heart, and then used to position a small plug or patch to close the hole.

You can find more information on atrial septal defects on the Mayo Clinic’s website.

Has Atrial Septal Defect Been Scientifically Linked To Zofran?

Yes.

In 2013, a team of researchers in Denmark reviewed every Danish birth record between the years of 1997 and 2010. In total, their study included 903,207 births. Mothers who had been prescribed Zofran were found to be 2.1 times more likely to give birth to children with an atrial septal defect.

One year later, Swedish scientists conducted a similar study, reviewing every birth record filed in Sweden between 1998 and 2012. The team found a 62% increase in the risk for cardiovascular defects in general, and more than a doubling in the risk for “cardiac septum defects.” This category of congenital heart defects includes atrial septal defects, as well as ventricular septal defects and atrioventricular septal defects.

The plaintiff from case 1:15-cv-10429 also notes that the data from a previous Danish study, conducted using birth records from more than 600,000 birth records, indicated that women who were prescribed Zofran’s active ingredient during the first trimester were 22% more likely to deliver babies with cardiac septal defects.

2. Right Ventricular Hypertension

Plaintiff’s daughter has also been diagnosed with right ventricular hypertension. This condition may be a result of the increased stress caused by her atrial septal defect. As we’ve mentioned, atrial septal defects force the heart to pump more, and harder, to supply the body with oxygen-rich blood. Over time, this additional effort can lead to dangerously high blood pressure, a condition called hypertension. 

In plaintiff’s child, increased blood pressure has forced her heart’s right ventricle, which gets filled with oxygen-poor blood and then pumps it out to the lungs, to bear the brunt of this abnormally high pressure.

Without proper treatment, patients suffering from hypertension are at an increased risk of developing hypertrophy, a condition in which the ventricle walls become thicker over time. But thick walls make it even harder for the heart to pump correctly and, in a vicious circle, hypertrophy can increase blood pressure further and force the walls to thicken even more.

According to the American Heart Association, “arrhythmias and symptomatic heart failure” are possible results of severe or untreated hypertension.

3. Aortic Arch Hypoplasia

The aorta is the body’s largest artery. Connected to the  left ventricle, the aorta carries oxygen-rich blood out to the rest of the body. A hypoplastic aorta is abnormally narrow, or blocked, at some point.

In specifying that her child suffers from aortic arch hypoplasia, the plaintiff in case 1:15-cv-10429 indicates that her daughter’s aorta is obstructed at an early juncture of the artery.

Just beyond the point at which it connects to the left ventricle, the aorta rises up and over a different artery, creating an “arch.” Above this arch, the aorta branches off into a network of narrower blood vessels, some of which lead upwards to nourish the brain while others descend to deliver oxygen to the trunk and legs. Because her aorta is narrow precisely where these vessels branch off, her body’s entire circulatory system could be adversely affected by this congenital defect.

According to Rady Children’s Hospital in San Diego, aortic arch hypoplasia is universally treated through open-heart surgery. In fact, their experts report that “before the advent of safe heart surgery, almost all […] babies would die from this blockage in the newborn or infant period.”

As we said earlier, the plaintiff in this Zofran birth defect lawsuit says that her daughter has undergone 13 separate surgeries to repair her congenital defects.

4. Bicuspid Aortic Stenosis

In a lawsuit filed on March 5, 2015 in the Superior Court for the State of California, County of San Francisco under case number CGC-15-544524, a family claims that exposure to Zofran during early pregnancy caused their child’s congenital heart defect: bicuspid aortic stenosis.

Think back to the aorta, the body’s largest artery, which is connected to the heart’s left ventricle and allows blood to flow toward other vital organs. The aortic valve lies between this artery and the left ventricle that supplies the body with oxygen-rich blood.

In healthy human hearts, this valve is equipped with three flaps, or leaflets, that prevent blood from trickling back into the ventricle after it has been pumped up through the aorta.

In the San Francisco complaint, plaintiffs indicate that their son’s aortic valve has only two leaflets. As a result of this abnormality, the valve is “stenotic,” hence the complaint’s use of the term stenosis. Essentially, the valve cannot open fully and thus cannot deliver an adequate supply of blood to the rest of the body.

While mild forms of aortic stenosis may be treated with medications alone, plaintiffs say that their son “will require continued monitoring and future surgeries to repair or replace his damaged valve.”

5. Supraventricular Tachycardia

On the same day that case CGC-15-544524 was filed in San Francisco, another Zofran lawsuit was filed in California. This complaint, registered under case number RG15761042, was filed in the Superior Court for the State of California, County of Alameda. In her claim, a mother from Oakland says that her son was born with supraventricular tachycardia (SVT) as a result of the Zofran she was prescribed for morning sickness.

Unlike the four congenital heart defects we’ve already discussed, SVT is a condition involving the heart’s electrical system.

Every time your heart pumps, the contraction of its chambers is being triggered by an electrical impulse. Healthy human hearts are triggered in this way at a relatively regular rate, around 60 to 100 times every minute.

In patients with SVT, something makes the impulses speed up. “Supraventricular” simply means “above the ventricles,” which implies that the electrical problem begins in the heart’s upper chambers, the atria. During episodes of atrial fibrillation, heart chambers flutter irregularly and go out of sync. In some cases, a patient’s heart rate can rise to 300 beats per minute.

In her complaint, the plaintiff refers to several common symptoms of SVT: “rapid breathing, shortness of breath and shallow breathing.” In severe cases of SVT, the heart’s blood supply is unable to keep up with the rapid bursts of accelerated beating, and heart failure is possible.

Lawsuits Suggest Other Congenital Heart Defects, But Diagnoses Remain Unspecified

We’ve covered birth defects named in three of the seven Zofran birth defect lawsuits that have been filed to date. Out of the four remaining complaints, two others have been filed for congenital heart defects, although specific diagnoses are not detailed in court documents.

“Hole In The Heart” Defects

Filed on February 12, 2015, America’s first Zofran birth defect lawsuit was registered under case number 2:15-cv-00709-PD in the United States District Court of the Eastern District of Pennsylvania.

In her complaint, a mother from Minnesota says that her two children were both born with congenital heart defects as a result of prenatal Zofran exposure. While the plaintiff does not detail the precise heart conditions with which her daughters were born, court documents refer to one child’s birth defect as a “hole in [the] heart.” This is an alternative term commonly used in place of “cardiac septal defect,” and it is possible that plaintiff’s child was born with either an atrial septal defect, ventricular septal defect or atrioventricular septal defect.

In another case, filed under case number 5:15-34 in the United States District Court for the Eastern District of Texas, Texarkana Division, a mother claims that prenatal exposure to Zofran caused her child to be born with “thickened arteries.” We mentioned this condition earlier, but called it hypertrophy in our discussion. Recall that a thickening of cardiac tissue is a frequent result of the increased blood pressure caused by a cardiac septal defect, and note that this mother’s child was born in 2014, only 8 months ago. Many congenital heart defects go undiagnosed for some time. Plaintiff also says that her child was diagnosed with a “heart murmur” shortly after birth. This sound, of blood “whooshing” abnormally in the heart, is often associated with the presence of a cardiac septal defect.