Safety and Pharmacokinetics of Famciclovir Single 1500 mg Dose in Adolescents With Recurrent Herpes Labialis

Inclusion Criteria:

• Outpatient males or females 12 to <18 years of age
• General good health with a documented history typical for recurrent herpes labialis
• Prodromal symptoms or active lesions suggestive of a recurrent episode of herpeslabialis (i.e. having had cold sores in the past) , with onset not exceeding 24 hoursuntil the time of study drug administration
• Adolescents participating in Pharmacokinetics (PK) part of the study may beenrolled without an active herpes labialis recurrence or with onset ofsigns/symptoms of a recurrent herpes labialis episode longer than 24 hours beforestudy drug administration, All adolescents participating in the pharmacokineticsassessments must fast for at least 8 hours prior to Visit 1 and be willing tofast for an additional 2 hours after study drug administration

Exclusion Criteria:

• Use of other investigational drugs within 30 days of enrollment
• History of hypersensitivity to famciclovir or penciclovir
• Inability to swallow tablets
• Body weight less than 40 Killograms (kg)
• History of malabsorption, unless a condition like celiac disease is stable and wellcontrolled, previous gastrointestinal surgery or radiation therapy that could affectdrug absorption or metabolism, or any condition that could interfere with drugabsorption, distribution, metabolism, or excretion
• Known renal insufficiency (calculated creatinine clearance <60 [Milliliters/Minutes]mL/min)
• Known severe hepatic impairment (Child-Pugh Class C)
• Significant skin disease such as atopic dermatitis or eczema that would interfere withassessment of oral/labial lesions
• Known to be immunocompromised or are receiving systemic or using topicalimmunosuppressive agents (including corticosteroids, tacrolimus and picrolimus) within 30 days of enrollment
• Concomitant use of probenecid
• Pregnant or nursing (lactating) females
• Females of child-bearing potential, UNLESS they are using two birth control methods.The two methods can be a double barrier method or a barrier method plus a hormonalmethod.