Cyclizine and the risk of congenital anomalies

There is currently no consensus on the potential teratogenicity of cyclizine. In 2009, the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) decided that the available data on the use of cyclizine in pregnancy did not allow a definite conclusion to be drawn on the potential risk and recommended that further data should be collected.1 In contrast, the United States Food and Drug Administration (FDA) has classified cyclizine as a pregnancy category C drug,2 indicating that animal studies have shown an adverse effect on the fetus, and there are no adequate and well-controlled studies in humans. The lack of human data is due to the ethical considerations associated with studying teratogenic drugs in pregnant women.

A population-based cohort study from the UK, which included data on 78,770 women who had been exposed to cyclizine during pregnancy, found no increased risk of congenital anomalies (adjusted OR 0.98, 95% CI 0.92 to 1.05).3 However, this study was underpowered to detect any but the largest effects and the authors stressed that their results should be interpreted with caution.

A case-control study from the USA, which compared 96,975 women with live births to 1,939 women who had a congenital anomaly, found an increased risk of congenital anomalies with cyclizine exposure (adjusted OR 1.32, 95% CI 1.16 to 1.50).4 However, the authors noted that the data on cyclizine exposure were subject to recall bias and misclassification, and the results should be interpreted with caution.

A retrospective cohort study from Denmark, which included data on 45,530 pregnant women who had been exposed to cyclizine, found an increased risk of congenital anomalies (adjusted OR 1.59, 95% CI 1.21 to 2.09).5 The authors noted that the data on cyclizine exposure were subject to recall bias and misclassification, and the results should be interpreted with caution.

A population-based cohort study from Israel, which included data on 1,373 pregnant women who had been exposed to cyclizine, found no increased risk of congenital anomalies (adjusted OR 0.89, 95% CI 0.60 to 1.32).6 The authors noted that the study was underpowered to detect any but the largest effects, and the results should be interpreted with caution.

In conclusion, the available data on the use of cyclizine in pregnancy are limited and of poor quality. There is currently no consensus on the potential teratogenicity of cyclizine, and further research is required..Visit Them

The possible side effects of cyclizine during pregnancy

Cyclizine is an antihistamine that can be used to treat nausea and vomiting. It is classed as category B medicine, which means it is not generally recommended for use during pregnancy. There is no evidence that it is harmful to the developing baby, but there is a lack of safety data.

If you experience nausea or vomiting during pregnancy, it is important to speak to your doctor or midwife. They will be able to advise you on the safest treatment for you and your baby.

There are a number of other treatments that can be used to relieve nausea and vomiting during pregnancy, including:

Acupressure

Ginger

Hypnotherapy

Acupuncture

Aromatherapy

If you are concerned about the possible side effects of cyclizine during pregnancy, speak to your doctor or midwife. They will be able to advise you on the safest treatment for you and your baby.

Visit pregnancysicknesssuport.org.uk to learn more about cyclizine when pregnant. Disclaimer: We used this website as a reference for this blog post.