Letermovir

The Basics

What is Letermovir?

Used to help prevent cytomegalovirus (CMV) infection and disease in certain people who have received a hematopoietic stem-cell transplant (HSCT).

Brand names for Letermovir

Prevymis

How Letermovir is classified

Antiviral Agents

Letermovir During Pregnancy

Letermovir pregnancy category

Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Letermovir while pregnant

No adequate human data are available to establish whether PREVYMIS poses a risk to pregnancy outcomes. In animal reproduction studies, embryo-fetal developmental toxicity (including fetal malformations) was observed in rats during the period of organogenesis at letermovir exposures (AUC) 11 times higher than human exposure at the recommended human dose (RHD). In rabbits, no embryo-fetal developmental toxicity was noted at exposures that were not maternally toxic (up to letermovir exposures 2 times higher than human exposure at the RHD). In a rat pre/post-natal development study, total litter loss was observed at maternal letermovir exposures approximately 2 times higher than human exposure at the RHD (see Data). The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Taking Letermovir While Breastfeeding

What are recommendations for lactation if you're taking Letermovir?

No information is available on the use of letermovir during breastfeeding. Because letermovir is 99% bound to plasma proteins, the amount in milk is likely to be very low. However, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Maternal / infant drug levels

No information is available on the use of letermovir during breastfeeding. Because letermovir is 99% bound to plasma proteins, the amount in milk is likely to be very low. However, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Possible effects of Letermovir on milk supply

Relevant published information was not found as of the revision date.

Possible alternatives to Letermovir

None listed