THIS MEDICATION IS UNLIKELY TO CAUSE HARM TO YOUR BABY:
Denavir should only be administered during pregnancy if clearly indicated. There have been limited human studies that have looked at the safety of Denavir during pregnancy, but animal studies indicate that taking Denavir during pregnancy poses a low risk of harm to the developing baby. Nursing infants are not expected to be exposed to this medication in significant amounts.
What is Denavir?
Denavir is a medication that is used for cold sores or fever blisters. Denavir is currently available as brand name medication only. The active ingredient in Denavir is penciclovir. Denavir is available as a topical cream and is applied to the face or lips every two hours for four days during the first symptoms of cold sores. It is available by prescription from your doctor.
What is Denavir used to treat?
Denavir is used to treat recurrent cold sores (Herpes labialis) in children over 12 years old, adolescents, and adults. Cold sores are blisters caused by the Herpes simplex virus that form around the lips and mouth. Cold sores are a common occurrence in Americans. The blisters typically last two weeks. However, people remain contagious until the cold sores scab, so avoiding close contact and sharing personal items should be avoided. The Herpes simplex virus can remain dormant in the body after cold sores heal, but the virus can reactivate and cause recurrent cold sores.
Moms can also experience cold sores. You can read about cold sores and their impact on pregnancy and newborns here.
How does Denavir work?
Denavir works by interfering with the DNA of the Herpes simplex virus which inhibits the growth and survival of the virus.
If I am taking Denavir, can it harm my baby?
Denavir is applied only to the skin and is not expected to be absorbed into the body. There have been limited human studies or case reports that have looked at the safety of this medication in pregnancy. Animal studies show that taking Denavir during pregnancy has a low risk of causing harm to your baby. It is recommended to only use this medication during pregnancy if clearly needed.
Evidence from animal studies with Denavir:
When Denavir was given to rats and rabbits at injectable doses 260 and 355 times the recommended human topical dose, no adverse effects were observed in the offspring or pregnancy. Doses of a drug similar to Denavir, given at doses 395 times the recommended human topical dose of this medication, caused formation of tumors in the mammary glands of female rats. Doses 100 times the maximum recommended human doses produced no tumors in male or female rats.
Evidence for the risks of Denavir in human babies:
It is unknown if Denavir crosses the human placenta to reach the developing baby. A 2010 study of 118 women exposed to topical Denavir during the first trimester of pregnancy found no significant increase in the risk of birth defects compared to 837,000 mothers not exposed to the medication during pregnancy.
Bottom line: Denavir should only be used during pregnancy if clearly indicated. Despite few human studies, animal studies suggest this medication poses a low risk during pregnancy. The absorption of this topical medication into the body is expected to be minimal.
If I am taking Denavir and become pregnant, what should I do?
If you are taking Denavir and become pregnant, you should contact your doctor immediately. Your doctor will determine if your medication is medically necessary, or if it should be discontinued until after the birth of your baby.
If I am taking Denavir, can I safely breastfeed my baby?
There are no human studies evaluating the safety of Denavir in nursing infants. Denavir is a topical medication and is not expected to be absorbed into the body or pass into a mother’s breast milk. The effects of this medication on a nursing infant are expected to be minimal. The manufacturer of this medication recommends consideration of discontinuing this medication while breastfeeding, but only after consideration of need for the medication by the mother.
Bottom line: The risk of harm to a nursing infant is expected to be low with this medication. The manufacturer of this medication recommends consideration of discontinuing this medication while breastfeeding after consideration of need of the medication by the mother.
If I am taking Denavir, will it be more difficult to get pregnant?
This has not been studied in women. Male rats and dogs receiving injectable doses of Denavir 1000 to 3000 times maximum recommended human doses experienced impaired fertility. Administration of a medication related to Denavir (penciclovir), known as famciclovir, did not negatively affect male fertility in human studies.
If I am taking Denavir, what should I know?
Denavir is a topical medication and is not expected to be absorbed into the body. It is recommended to only use this medication during pregnancy if clearly needed.
The effects of this medication on a nursing infant are expected to be minimal. The manufacturer recommends discontinuing this medication while breastfeeding.
If I am taking any medication, what should I know?
This report provides a summary of available information about the use of Denavir during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.
You may find Pregistry's expert reports about the individual medications used to treat infections here, and our report about Herpes Types 1 and 2 here. Additional information can also be found in the resources below.
For more information about Denavir during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links.
American Academy of Dermatology: Cold sores
US Food and Drug Administration: Denavir Prescribing Information
General information
It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.
For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.
It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.
If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.
If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.
Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.