Acyclovir (Zovirax)/Valacyclovir (Valtrex)
Organization of Teratology Information Specialists, 2004 See article at otispregnancy.org
[len:12788, cleaned:] D:\wwwroot\tripdatabaseplus_live\control\reindex\html\E555C5C6-9C65-4542-BAFC32DE52ADFFB1 For more information regarding OTIS or a Teratology Information Service in your area, call OTIS Information at (866) 626-6847 or visit us online at: www.OTISpregnancy.org. Acyclovir (Zovirax)/Valacyclovir (Valtrex) and Pregnancy The information below will help you determine if your exposure to acyclovir or valacyclovir represents an increased fetal risk. With every pregnancy, all women have a 3 to 5 percent chance to have a baby with a birth defect. The information contained in this fact sheet should not be used as a substitute for the medical care and advice of your health care provider. What is acyclovir The most common use for acyclovir is to treat genital Acyclovir or Zovirax, as it is commonly known is an herpes. Up to half of all acyclovir users are women of antiviral medication used to treat cold sores and genital childbearing age and many have become pregnant while herpes caused by the herpes virus. It is also prescribed to taking the drug. An oral medication or one taken treat chickenpox and shingles due to the related herpes intravenously can enter the baby's body and has been virus. The FDA approved its use in 1984. found in the umbilical cord and amniotic fluid. A Unfortunately, it does not cure the disease and infections pregnancy registry was started by the manufacturer, can return at a later time. Acyclovir is prescribed as a Glaxo Wellcome Co. and the Centers for Disease Control cream or ointment (topical use), oral tablets, or (CDC) to look at the effects of acyclovir on the intravenous liquid to relieve pain, speed recovery, and developing baby. Of the 311 births after first trimester prevent viral shedding. More recently, acyclovir has exposure to acyclovir, no increase in birth defects beyond been used in combination with AZT, to treat AIDS the general population was noted. Animal studies with patients. exposures during the first-trimester also confirm these results. The pregnancy registry ended on 4/30/99, but the Is valacyclovir the same as acyclovir? manufacturer requests that exposures to acyclovir or valacyclovir during pregnancy be reported to its Valacyclovir is very similar to acyclovir and is often voluntary reporting system at the Glaxo Wellcome Inc. used to treat the same types of infections. A common Customer Response Center by calling 1-888-825-5249. name for it is Valtrex. Since valacyclovir is changed to acyclovir once in the woman's body, the effects on the Is there a concern for birth defects if my partner was pregnancy and breastfeeding are thought to be the same. taking acyclovir when I became pregnant? I take acyclovir as needed to treat herpes. Should I stop Since acyclovir does not cause changes in the genetic using it before I try to get pregnant? material of the sperm, your partner's use of acyclovir is unlikely to increase the risk for birth defects. No. You should not stop taking any medications without first talking with your doctor. As with any medication Can I use acyclovir during my second or third that is taken during pregnancy, the benefits to the mother trimester? and baby should outweigh the possible risks when deciding whether to continue its use. Based on the manufacturer's pregnancy registry and other animal studies, it appears that acyclovir use in the Can acyclovir use by my partner or myself make it more second and third trimesters of pregnancy do not increase difficult for me to become pregnant? the risks to the developing baby. Of the 69 births after second trimester exposures to acyclovir and of the 106 In animal studies, high doses of acyclovir affected sperm births after third trimester exposure, no increase in birth production. A follow-up study in 20 men did not find defects was noted. Despite the small numbers from each lower sperm production when they were given high doses group, these results are reassuring for six months. There have not been any studies that looked at the effect of acyclovir on female reproduction. I have a cold sore on my lip, could acyclovir ointment At this point, it does not appear to have a negative effect. cause birth defects? I have been taking acyclovir for genital herpes and just Topical use of acyclovir ointment has not been well- found out that I am pregnant. Could it cause birth studied but is not suspected of causing birth defects defects during the first trimester? because it is not easily absorbed through the skin. Are there any situations in which using acyclovir Andrews EB (1994) Acyclovir does not increase risk in during pregnancy is necessary for the health of the pregnancy. Am Pharm NS34:6. mother and baby? Boyd K, Walker E (1988) Use of acyclovir to treat chickenpox in pregnancy. Br Med J (Clin Res Ed) 296:393-4. Braig S, Luton D, Sibony O, Edlinger C, Boissinot C, Blot Acyclovir is often prescribed during pregnancy when the P, Oury JF (2001) Acyclovir prophylaxis in late pregnancy prevents mother has a primary genital herpes infection. A recurrent genital herpes and viral shedding. Eur J Obstet Gynecol "primary" infection means it is the first time for the Reprod Biol 96:55-8. Brocklehurst P, Carney O, Helson K, Kinghorn G, Mercey infection. Primary infection can be life threatening or D, Mindel A (1990) Acyclovir, herpes, and pregnancy. Lancet lead to severe complications in the pregnancy. A rare but 336:1594-5. serious infection called varicella pneumonia also requires Brown ZA, Baker DA (1989) Acyclovir therapy during treatment with acyclovir, which is often given pregnancy. Obstet Gynecol 73:526-31. intravenously. No side effects were seen in these babies Centers for Disease Control. Pregnancy outcomes following systemic prenatal acyclovir exposure _ June 1, 1984-June after treatment with acyclovir. 30, 1993. MMWR 1993, 42:806-809. Douglas JM, Jr., Davis LG, Remington ML, Paulsen CA, Does exposure to acyclovir cause an increased risk for Perrin EB, Goodman P, Conner JD, et al (1988) A double-blind, miscarriage or infant death? placebo-controlled trial of the effect of chronically administered oral acyclovir on sperm production in men with frequently recurrent genital herpes. J Infect Dis 157:588-93. Miscarriages from acyclovir use during the first trimester Fletcher CV (1992) The placental transport and use of were less than the expected number in the general acyclovir in pregnancy. J Lab Clin Med 120:821-2. population. Of the 425 first trimester pregnancies in the Frenkel LM, Brown ZA, Bryson YJ, Corey L, Unadkat JD, registry, 11% resulted in miscarriages. In general, about Hensleigh PA, Arvin AM, et al (1991) Pharmacokinetics of acyclovir in the term human pregnancy and neonate. Am J Obstet Gynecol 15% of all pregnancies result in a miscarriage during the 164:569-76. first-trimester. There were no reports of pregnancy loss Kimberlin DF, Weller S, Whitley RJ, Andrews WW, Hauth during the second trimester and less than 1% in the third JC, Lakeman F, Miller G (1998) Pharmacokinetics of oral trimester. valacyclovir and acyclovir in late pregnancy. Am J Obstet Gynecol 179:846-51. Klug, S, Stahlmann, R, Golor, G, et al. (1992) Acyclovir in Can acyclovir get into my baby's body? pregnant marmoset monkeys-oral treatment. Teratology 45:472. Hale, Thomas, PhD (2000) Medications and Mother's Milk, Yes, acyclovir can get into the baby's body but the 9th edition, Pharmasoft Publishing. amount measured was very low and did not cause health Leen CL, Mandal BK, Ellis ME, Brettle RP (1987) Acyclovir and pregnancy. Br Med J (Clin Res Ed) 294:308. problems. The baby's kidneys are able to remove Mamede JA, Simoes Mde J, Novo NF, Juliano Y, Oliveira- acyclovir from the body. Filho RM, Kulay Junior L (1995) Chronic effects of azidothymidine and acyclovir on pregnant rats. Gen Pharmacol 26:523-6. Can I use acyclovir while breastfeeding my baby? Moore HL, Jr., Szczech GM, Rodwell DE, Kapp RW, Jr., de Miranda P, Tucker WE, Jr. (1983) Preclinical toxicology studies with acyclovir: teratologic, reproductive and neonatal tests. Fundam The American Academy of Pediatrics has approved the Appl Toxicol 3:560-8. use of acyclovir while breastfeeding. Acyclovir does Mutalik S, Gupte A, Gupte S (1997) Oral acyclovir therapy enter breast milk, however the amount of medication the for varicella in pregnancy. Int J Dermatol 36:49-51. baby would receive is very low. Based on the data Prober CG (2001) Management of the neonate whose mother received suppressive acyclovir therapy during late pregnancy. available, acyclovir does not cause health concerns for Pediatr Infect Dis J 20:90-1. the baby. If the medication is used as a cream or Sheffield JS, Fish DN, Hollier LM, Cadematori S, Nobles ointment on the nipples, the area should be cleaned prior BJ, Wendel GD, Jr. (2002) Acyclovir concentrations in human breast to nursing. Acyclovir is commonly given to newborns milk after valaciclovir administration. Am J Obstet Gynecol 186:100- 2. and does not typically cause problems for the baby. Smego RA, Jr., Asperilla MO (1991) Use of acyclovir for varicella pneumonia during pregnancy. Obstet Gynecol 78:1112-6. Spangler JG, Kirk JK, Knudson MP (1994) Uses and safety July 2003. of acyclovir in pregnancy. J Fam Pract 38:186-91. Copyright by OTIS. Stiffman MN, Adam P (1997) Acyclovir in pregnancy for Reproduced by permission. primary prevention of neonatal herpes. J Fam Pract 44:29-30. Stahlmann, R, golor, G, Klug, S, et al (1992) Acyclovir in pregnant marmoset monkeys-intravenous treatment. Teratology 45:453. Stray-Pedersen B (1990) Acyclovir in late pregnancy to References: prevent neonatal herpes simplex. Lancet 336:756. Tyring SK, Baker D, Snowden W (2002) Valacyclovir for Andrews EB, Yankaskas BC, Cordero JF, Schoeffler K, herpes simplex virus infection: long-term safety and sustained Hampp S (1992) Acyclovir in pregnancy registry: six years' efficacy after 20 years' experience with acyclovir. J Infect Dis 186 experience. The Acyclovir in Pregnancy Registry Advisory Suppl 1:S40-6. Committee. Obstet Gynecol 79:7-13.
