Xerese Drug Information

XERESE, a combination of acyclovir, a herpes simplex virus deoxynucleoside analog DNA polymerase inhibitor, and hydrocortisone, a corticosteroid, is indicated for the early treatment of recurrent herpes labialis (cold sores) to reduce the likelihood of ulcerative cold sores and to shorten the lesion healing time in adults and children (6 years of age and older). XERESE, a combination of acyclovir, a herpes simplex virus deoxynucleoside analog DNA polymerase inhibitor, and hydrocortisone, a corticosteroid, is indicated for the early treatment of recurrent herpes labialis (cold sores) to reduce the likelihood of ulcerative cold sores and to shorten the lesion healing time in adults and children (6 years of age and older).

Topically apply XERESE 5 times per day for 5 days. Therapy should be initiated as early as possible after the first signs and symptoms (i.e., during the prodrome or when lesions appear). For each dose, topically apply a quantity of XERESE sufficient to cover the affected area, including the outer margin. Avoid unnecessary rubbing of the affected area to avoid aggravating or transferring the infection.

For children 6 years of age and older, the dosage is the same as in adults. Topically apply XERESE 5 times per day for 5 days. Therapy should be initiated as early as possible after the first signs and symptoms (i.e., during the prodrome or when lesions appear).

Adverse Reactions in Clinical Trials

Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in clinical practice. The safety data derived from XERESE clinical trials reflect exposure to XERESE in 1,056 subjects with recurrent herpes labialis treated 5 times daily for 5 days. The most common adverse reactions (<1%) were local skin reactions, and occurred in the area of the application site, including: - Drying or flaking of the skin; burning or tingling following application; erythema; pigmentation changes; application site reaction including signs and symptoms of inflammation.

Contact dermatitis following application has been observed when applied under occlusion in dermal safety trials. Where contact sensitivity tests have been conducted, the reactive substances were hydrocortisone or a component of the cream base. A trial enrolling 225 healthy adults was conducted to evaluate the contact sensitization potential of XERESE using repeat insult patch testing methodology.

Of 205 evaluable subjects, one confirmed case (0.5%) of sensitization to hydrocortisone and 2 additional cases (1.0%) of possible sensitization to the XERESE base were identified. Additionally, one subject developed a contact allergy in the photosafety study to propylene glycol, one of the inactive ingredients of the cream base. Dermal tolerance was assessed in a 21-day cumulative irritation trial in 36 healthy subjects.

XERESE, its cream base and Zovirax ® (acyclovir) Cream 5% all showed a high and cumulative irritation potential under occlusive and semi-occlusive conditions. Photoallergic potential and phototoxicity were assessed in two trials in 50 and 30 healthy volunteers, respectively. No photoallergic or phototoxicity potential was identified for XERESE.

No drug interaction studies have been performed with XERESE. No drug interaction studies have been performed with XERESE.

Pregnancy Risk Summary There are no available data on XERESE use in pregnant women. However, published observational studies over decades of use of topical acyclovir and low and medium potency topical corticosteroids during pregnancy have not established any association between use of these products and major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data). Animal reproduction studies have not been conducted with XERESE. Systemic exposure of acyclovir and hydrocortisone following topical administration of XERESE is expected to be minimal. Animal reproduction studies with systemic exposure of acyclovir and hydrocortisone have been conducted.

Refer to acyclovir and hydrocortisone prescribing information for additional details. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Human Data While available studies cannot definitively establish the absence of risk, published data from multiple large observational studies have not established an association with the use of topical acyclovir or low and medium potency topical corticosteroids (including hydrocortisone) during pregnancy and major birth defects, miscarriage, or adverse maternal or fetal outcomes. Available studies have methodological limitations including whether women who filled a prescription actually took the medication, non-randomized design, retrospective data collection, and the inability to control for confounders such as underlying maternal disease and use of concomitant medications.

Pediatric Use Safety and effectiveness in pediatric subjects less than 6 years of age have not been established.

Overdosage by topical application of XERESE is unlikely because of minimal systemic exposure.