Baraclude (Entcavir) and Pregnancy

It is very difficult to find information on the effects of Baraclude on pregnancy. With some digging, some information, while not extremely informative, can be found.

Baraclude is an antiviral drug used to treat Hepatitis B. It can cause the side effects of increased risks of cancer, liver damage, kidney damage, headache, nausea, dizziness, and so on. With pregnancy, laboratory testing has placed it in Category C: animal tests have been conducted and are somewhat safe, but tests on humans have not been conducted (and it is difficult to do conduct these tests in a controlled manner).

The statistical information that can be found, though is this:

  • In testing on rats, doses at 28 times the highest recommended human dose (1 mg/day) caused no problems. Doses at 3100 times the highest recommended dose caused severe problems in embryos, specifically deformities.
  • In testing on rabbits, doses at 212 times the highest recommended human dose caused no problems. Doses at 883 times the highest recommended dose caused severe problems in embryos, again referring to deformities.

That is the basic data given by Bristol-Myers Squibb, which is probably all the data provided for FDA testing. However, there is some more limited data.

Based on the specific molecule of the Baraclude drug, Baraclude is passed to the embryo during pregnancy and during breastfeeding. Data from the Antiretroviral Pregnancy Registry (1989-2009), which tracks the effects of Baraclude-class drugs on pregnancy, suggests that human embryos experience deformities at a rate of under 3% when exposed to one or more of these drugs, which may or may not include Baraclude. The data is not significantly different compared to embryos not exposed to these drugs, indicating some safety. It is important to note that Baraclude is not specifically mentioned in this grouping. However, for 10 reported cases specifically using Baraclude, no defects were found.

This would imply that Baraclude is reasonably safe for use during pregnancy. However, there are no firm statistics to prove this, and as with any medicine, serious unexpected side effects may occur.