The history of Paxil gives us another look at how our medical system, consisting of medical researchers, drug companies, doctors and the FDA, do a poor job protecting moms and their babies. Did you know most drugs aren't even tested initially on women for safety? Men are chosen for testing because they don't have cycles and fluctuating hormones which can affect results. An added benefit to testing only on men is not risking testing on pregnant women which could be a huge liability issue. In my blog piece "Let's Talk about Off Label Use, Cytotec and You" we discussed how difficult it would be to find pregnant women who would willingly sign up to be part of a drug experiment. I explained about one of the ways the drug companies and doctors get around this thorny issue. The Paxil case illustrates another way. It is important to remember that most of what we know about the safety of any given medication taken during pregnancy and lactation is known only in hind sight.
The Story of Paxil, a cautionary tale...
Approved by the FDA in 1992 doctors begin to prescribe it to treat depression, generalized anxiety disorder (GAD), social anxiety disorder, panic disorder (PD), and obsessive compulsive disorder (OCD), and posttraumatic stress disorder (PTSD).
Six years later...
In 1998 the drug company that makes Paxil, GlaxoSmithKline, internal review found an alarmingly high number of Paxil birth defect reports. Early results of two studies showed that women who took Paxil during the first trimester of pregnancy (before they might even know they are pregnant!) were about two times as likely to have a baby with a heart defect as women who received other antidepressants. However, the information was not turned over to the FDA!!!
Seven years later...
In December 2005 the FDA (US Food and Drug Administration) issued a public health advisory warning of increased risk of Paxil birth defects if used while pregnant. Particularly, during the first trimester of pregnancy.
One year later...
The American Medical Association estimated that 40,000 pregnant women in the US were taking antidepressants in 2006. GlaxoSmithKline also stated that in that year about 25 percent of prescriptions for Paxil were written for women of childbearing age.
Two years later...
Paxil generated about $942 million in sales in 2008 from Paxil.
Eighteen years after FDA approval of safety and twelve years after GlaxoSmithKline knows the drug isn't safe for pregnant moms...
In 2010 Paxil is the only SSRI(Selective Serotonin Reuptake Inhibitor) on the market that is classified by the FDA as a Category D drug. Category D means that studies in pregnant women have demonstrated a risk to the fetus. The studies mentioned show a greater risk for babies whose moms took Paxil over other SSRIs. What about comparing the risk between moms who take any SSRIs and moms who don't take any SSRIs? Perhaps we should find out if SSRIs are simply too risky for women of childbearing age unless they are also on a very effective birth control method?
Here's why all SSRIs may be a problem. This group of antidepressants are designed to relieve the symptoms of depression by blocking the reuptake of the chemical serotonin by certain nerve cells in the brain. With more serotonin in the brain, mood is improved. However, Maternal Serotonin plays a crucial role in fetal heart, lung and brain development. Further in the case of Paxil it is known to cross the placenta. So not only are you changing the unique balance of the maternal brain chemicals that effect fetal development you are also directly drugging your growing baby's brain during critical developmental stages.
Paxil, as well as other SSRIs, have been linked to Persistent Pulmonary Hypertension in the Newborn (PPHN) – a devastating condition affecting the heart and lungs of newborn infants. Babies are unable to breathe properly due to constricted blood vessels which cut off oxygen to the blood and cause damage to other organs such as brain and kidneys.
Known Paxil birth defects include:
Spina Bifida: a developmental birth defect caused by the incomplete closure of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through the opening in the bones. There may or may not be a fluid-filled sac surrounding the spinal cord.
Heart Defects: atrial and ventricular septal heart defects (holes in the walls of the chambers of the heart).
Anencephaly: condition in which the portion of the neural tube which will become the cerebrum(the dominant part of the brain) does not close, and encephalocele, which results when other parts of the brain don't appropriately fuse .
These frightening scientific descriptions can never express the personal devastation and family tragedies they represent. My heart breaks.