Acyclovir

INDICATIONS AND USAGE Acyclovir ointment 5% is indicated in the management of initial genital herpes and in limited non-life threatening mucocutaneous Herpes simplex virus infections in immunocompromised patients.

DOSAGE AND ADMINISTRATION Apply sufficient quantity to adequately cover all lesions every 3 hours, 6 times per day for 7 days. The dose size per application will vary depending upon the total lesion area but should approximate a one-half inch ribbon of ointment per 4 square inches of surface area. A finger cot or rubber glove should be used when applying acyclovir ointment to prevent autoinoculation of other body sites and transmission of infection to other persons. Therapy should be initiated as early as possible following onset of signs and symptoms.

WARNINGS Acyclovir ointment 5% is intended for cutaneous use only and should not be used in the eye.

CONTRAINDICATIONS Acyclovir ointment 5% is contraindicated in patients who develop hypersensitivity to the components of the formulation.

Drug Interactions Clinical experience has identified no interactions resulting from topical or systemic administration of other drugs concomitantly with acyclovir ointment 5%.

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 acyclovir, acyclovir concentrations have been documented in breast milk in two 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.

ADVERSE REACTIONS In the controlled clinical trials, mild pain (including transient burning and stinging) was reported by about 30% of patients in both the active and placebo arms; treatment was discontinued in two of these patients. Local pruritus occurred in 4% of these patients. In all studies, there was no significant difference between the drug and placebo group in the rate or type of reported adverse reactions nor were there any differences in abnormal clinical laboratory findings. Observed During Clinical Practice Based on clinical practice experience in patients treated with acyclovir ointment in the U.S., spontaneously reported adverse events are uncommon. Data are insufficient to support an estimate of their incidence or to establish causation. These events may also occur as part of the underlying disease process. Voluntary reports of adverse events that have been received since market introduction include: General: Edema and/or pain at the application site. Skin: Pruritus, rash.