General: The recommended dosage, frequency of applications, and length
of treatment should not be exceeded (see DOSAGE AND ADMINISTRATION).
There are no data to support the use of ZOVIRAX Ointment (acyclovir ointment) 5% to prevent transmission
of infection to other persons or prevent recurrent infections when applied in
the absence of signs and symptoms. ZOVIRAX Ointment (acyclovir ointment) 5% should not be used for
the prevention of recurrent HSV infections. Although clinically significant
viral resistance associated with the use of ZOVIRAX Ointment (acyclovir ointment) 5% has not been
observed, this possibility exists.
Carcinogenesis, Mutagenesis, Impairment of Fertility: Systemic exposure
following topical administration of acyclovir is minimal. Dermal carcinogenicity
studies were not conducted. Results from the studies of carcinogenesis, mutagenesis,
and fertility are not included in the full prescribing information for ZOVIRAX
Ointment 5% due to the minimal exposures of acyclovir that result from dermal
application. Information on these studies is available in the full prescribing
information for ZOVIRAX Capsules, Tablets, and Suspension and ZOVIRAX for Injection.
Pregnancy: Teratogenic Effects: Pregnancy Category B. Acyclovir
was not teratogenic in the mouse, rabbit, or rat at exposures greatly in excess
of human exposure. There are no adequate and well-controlled studies of systemic
acyclovir in pregnant women. A prospective epidemiologic registry of acyclovir
use during pregnancy was established in 1984 and completed in April 1999. There
were 749 pregnancies followed in women exposed to systemic acyclovir during
the first trimester of pregnancy resulting in 756 outcomes. The occurrence rate
of birth defects approximates that found in the general population. However,
the small size of the registry is insufficient to evaluate the risk for less
common defects or to permit reliable or definitive conclusions regarding the
safety of acyclovir in pregnant women and their developing fetuses. Systemic
acyclovir should be used during pregnancy only if the potential benefit justifies
the potential risk to the fetus.
Nursing Mothers: It is not known whether topically applied acyclovir
is excreted in breast milk. Systemic exposure following topical administration
is minimal. After oral administration of ZOVIRAX, acyclovir concentrations have
been documented in breast milk in 2 women and ranged from 0.6 to 4.1 times the
corresponding plasma levels. These concentrations would potentially expose the
nursing infant to a dose of acyclovir up to 0.3 mg/kg per day. Nursing mothers
who have active herpetic lesions near or on the breast should avoid nursing.
Geriatric Use: Clinical studies of ZOVIRAX Ointment (acyclovir ointment) did not include
sufficient numbers of subjects aged 65 and over to determine whether they respond
differently from younger subjects. Other reported clinical experience has not
identified differences in responses between the elderly and younger patients.
Systemic absorption of acyclovir after topical administration is minimal (see
CLINICAL PHARMACOLOGY).
Pediatric Use: Safety and effectiveness in pediatric patients have not
been established.
Last reviewed on RxList: 8/13/2008
This monograph has been modified to include the generic and brand name in many instances.