Zyrtec

Is it ok to take zyrtec, I am 4 weeks pregnant?

[David Tinkelman, M.D.]

The safety of Zyrtec, when taken by the mother during pregnancy, has not been proven with an absolute degree of certainty but the FDA states below** that “Limited published data with cetirizine suggests it is relatively safe during the first trimester (first 12 weeks)  of pregnancy.

The FDA  has placed this drug in Pregnancy Category B*** (see table below for explanation).  LexiComp notes that “safety data is limited.”

The bottom line is that Zyrtec appears to pose no threat to the fetus but that belief has not been confirmed with a high degree of certainty.

I hope the following helps.

I also strongly suggest that you discuss this question with your OB/GYN physician and also with your child’s probably Pediatrician.

Good luck,

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The following is from online LexiComp, a highly regarded source of information on pharmaceutical products,for patients and healthcare providers.
The following information on Zyrtec is from their site:

Pregnancy Considerations Maternal use of cetirizine has not been associated with an increased risk of major malformations. The use of antihistamines for the treatment of rhinitis during pregnancy is generally considered to be safe at recommended doses. Although safety data is limited, cetirizine may be a preferred second generation antihistamine for the treatment of rhinitis during pregnancy.

The following is from the Food and Drug Administration (FDA) statement on this drug, dated September 16, 2010

4.1 DEATHS AND FETAL EXPOSURES (N=6)
This case series includes six fetal exposures to levocetirizine (3 deaths and 3 healthy newborns) resulting from maternal ingestion. Appendix 8.4 describes the three death cases in detail.
According to the Prescribing Information, levocetirizine is pregnancy category B*. (see table below).In rats and rabbits, levocetirizine was not teratogenic at oral doses up to 260 and 120 mg/kg, respectively (approximately 200 and 100 times the maximum recommended daily oral dose in adults on a mg/m2 basis). There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, levocetirizine should be used during pregnancy only if clearly needed.
Women commonly use antihistamines during pregnancy, with the reported prevalence of antihistamine use ranging from 4–10% during the first trimester to 8–15% at any time during pregnancy.3 A search of the National Library of Medicine’s PubMed did not identify published studies of the effect of levocetirizine on pregnancy outcomes. **Limited published data with cetirizine suggests it is relatively safe during the first trimester.4
Three percent of all newborns born in the United States have a major structural malformation detectable at birth.5 Since the birth defects observed in this case series (spina bifida and tetralogy of Fallot) are common and women often use antihistamines during pregnancy, it is possible that exposure to levocetirizine during pregnancy and a defect are temporally but not causally related. We did not detect a specific pattern of defects from the small number of fetal exposures to levocetirizine reported in the AERS database. In the case that reported multiple defects and fetal loss after amniocentesis, we cannot rule of the contributory role of procedure-related complications of amniocentesis.6 Furthermore, not all of the cases indicated that the mothers took levocetirizine during the entire period of organogenesis. Therefore, the outcomes of exposed pregnancies in this case series cannot be combined to inform us on teratogencity. Overall, these reports do not produce a strong safety signal at this time.


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United States FDA Pharmaceutical Pregnancy Categories***
Pregnancy Category A Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
Pregnancy Category B Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Pregnancy Category C Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Pregnancy Category D There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Pregnancy Category X Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.
One characteristic of the FDA definitions of the pregnancy categories is that the FDA requires a relatively large amount of high-quality data on a pharmaceutical for it to be defined as Pregnancy Category A. As a result of this, many drugs that would be considered Pregnancy Category A in other countries are allocated to Category C by the FDA.