Claritin Cleared of Birth Defect Hypospadias

By Barbara K. Hecht, Ph.D. and Frederick Hecht, M.D.
Medical Authors and Editors,

The allergy drug Claritin has been found not to cause the birth defect hypospadias. Claritin (loratadine) is a popular non-sedating antihistamine.

Hypospadias is a relatively common congenital malformation (birth defect). It affects one boy in every one to two hundred born in the US. In hypospadias, the urethral opening is located along the underside of the penis, scrotum, or perineum. Hypospadias is classified in order of increasing severity as first, second, or third degree. The condition often requires surgery.

The Fear of a Birth Defect

The fear that Claritin might cause hypospadias dates to 2002. That year a Swedish study reported that the prevalence of hypospadias was twice normal among boys whose mothers had taken Claritin during pregnancy. However, insufficient data were available to determine the severity of the hypospadias, and the study did not control for confounding variables such as a family history of hypospadias.

In 2003, a small prospective study failed to confirm the association of Claritin with hypospadias. The study done in 4 countries indicated that 5 of 142 pregnancies in women exposed to Claritin resulted in infants with major malformations, a prevalence consistent with that of the general population. None had hypospadias.

New Study by the CDC