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

AEs are defined as any unfavorable and unintended diagnosis, symptom, sign (including an abnormal laboratory finding), syndrome or disease which either occurs during study, having been absent at baseline, or, if present at baseline, appears to worsen. Serious adverse events are any untoward medical occurrences that result in death, are life threatening, require (or prolong) hospitalization, cause persistent or significant disability/incapacity, result in congenital anomalies or birth defects, or are other conditions which in judgment of investigators represent significant hazards.

Participants with laboratory values outside the defined normal range were graded as clinically significant laboratory abnormalities. Laboratory values were assessed according to the National Cancer Institute- Common terminology criteria for Adverse Events (NCI-CTCAE). Hematology, Urinalysis and clinical chemistry were reported .

Tmax was defined as the time to reach maximum plasma concentration. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using a validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method. The limit of quantification was 0.15 microgram (µg)/milliliter (mL) for both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.

Cmax was defined as the maximum observed plasma concentration. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using LC/MS/MS method. The limit of quantification was 0.15 µg/mL for both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.

AUC 0-tlast was defined as the area under the plasma concentration-time curve from time zero up to the last quantifiable concentration (Clast) calculated by the linear trapezoidal rule. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using LC/MS/MS method. The limit of quantification was 0.15 µg/mL for both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.

AUC 0-infinity was defined as the area under the plasma concentration time curve from time zero to infinity = AUC 0-tlast + C last /λ z, where λz is the apparent elimination rate constant estimated by linear regression analysis of the terminal portion of the log-linear plasma concentration-time curve. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using LC/MS/MS method. The limit of quantification was 0.15 µg/mL for both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.

T½ was defined as the apparent terminal elimination half-life= ln 2/ λz. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using LC/MS/MS method. The limit of quantification was 0.15 µg/mL For both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.

CL/F was defined as the apparent oral clearance of penciclovir from plasma = dose of famciclovir*0.7884/AUC 0-inf, where 0.7884 is the ratio of the molecular weight of penciclovir (253.3 g/mol) to famciclovir (321.3 g/mol). F is the bioavailability of penciclovir after oral administration of famciclovir. Penciclovir (active metabolite from famciclovir) and 6-deoxypenciclovir (first intermediate metabolite from famciclovir) were determined by using LC/MS/MS method. The limit of quantification was 0.15 µg/mL for both compounds. Calculations were done in WinNonlin 5.0.1, using non-compartmental methods.