Medications that can cause birth defects

MedicationsThere has been a lot of news coverage about the Zika virus and the birth defects it can cause if a woman is infected during pregnancy.  Did you know that the medication in your cabinet may also cause harm to a developing fetus?

When you (or your teenage daughter) start a new medication, it might be the last thing on your mind to think about whether that medication can cause birth defects, otherwise known as a teratogen. After all, if you’re not trying to get pregnant (or you don’t think your teen is having sex, right?), it may not be the first thing you think of when you or your teen start a medication. But…what if? What if you or someone you love were at risk of getting pregnant while on a medication that causes birth defects?

Some medications are famous (notorious?) for the birth defects they can cause.  Thalidomide, a medication at one time (1950s-60s) used as a sedative and cure for morning sickness, caused severe limb defects in newborn babies of mothers who took the medication.  Diethylstilbestrol (DES) is a synthetic estrogen that had been used in pregnancy to prevent miscarriage in the 1940s-60s, and was later shown to cause a specific deformity in the uterus of daughters exposed to DES and put these daughters at high risk for a rare vaginal cancer.  Accutane (generic name Isotretinoin), used to treat severe acne in adolescents, can lead to facial deformities and brain defects in their offspring if taken during pregnancy.  There are many, many medications, both those available by prescription or available over the counter, that have been shown to be harmful to fetuses. To communicate the potential teratogenic risk of a medication to the prescriber, the United States Food and Drug Administration (FDA) currently uses an evidence-based grading system as part of product labeling that categorizes medications by potential for teratogenic risk (eg, category A are those with no demonstrated risk, categories D and X are those associated with definite risk and positive evidence of fetal harm). Even medicines which are widely used, like blood pressure medicines or antibiotics are on the list of those ranked D or X, including (but not limited to):

  • Certain over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), like  aspirin, ibuprofen, or naproxen
  • Angiotensin-converting enzyme (ACE) inhibitors used to treat high blood pressure (Lisinopril, captopril, etc)
  • Statins used to treat high cholesterol (lovastatin, atorvastatin, etc)
  • Antibiotics (tetracylines, sulfa drugs, ciprofloxacin, etc.)
  • Benzodiazepines, used as anti-anxiety or sleep medication (lorazepam, clonazepam, diazepam, etc)
  • Warfarin (blood thinner)
  • Isotretinoin (Accutane, an acne medication)
  • Certain antiseizure medications, like phenytoin or valproic acid
  • Certain antidepressants and other psychiatric medications, like lithium

I’m not telling you to stop taking your medications if they are on this list; these medications definitely have specific uses that can be necessary for your health (and no medications should be stopped without first consulting your health care provider).  Even Thalidomide is still used as a treatment for multiple myeloma (but now monitored by System for Thalidomide Education and Prescribing Safety (S.T.E.P.S.) program. I am asking you to pay attention to the counseling that you receive whenever you are prescribed a medication.   When your doctor starts you on a new drug or asked about what medications you’re currently taking, did he or she ask about what kind of contraception you’re using? Did the doctor screen your teenager about his/her sexual activity prior to starting a potentially teratogenic medication? A recent study in Pediatrics found that doctors aren’t asking enough about reproductive health in their adolescent and young adult female patients or providing enough education when it comes to telling patients the risks associated with potentially teratogenic treatments and medications.

There are some companies that have taken steps to make sure that their teratogenic medication is prescribed properly. Accutane, a fairly common treatment for severe nodular acne, has a specific iPLEDGE program, which is a mandatory sexual health discussion (and negative pregnancy test as well as contraception prescription if potential for sexual activity) between the prescriber and the patient. Often, pharmacists will provide a stop-gap to make sure that the patient is aware of the dangers of certain medications during pregnancy. However, with other drugs like blood pressure medicines or antibiotics, it may not be the first thing either you or your health care provider thinks about, unless you express that you are trying to get pregnant or think that you could be pregnant.

It’s important to advocate for yourself and your teen as a patient and make sure you understand the risks and benefits of any medications that you’re considering taking – and ask your health care provider if things aren’t clear!