Antiherpetic medication use and the risk of gastroschisis: findings from the National Birth Defects Prevention Study, 1997-2007.

BACKGROUND: Previous studies examining the teratogenic effects of antiherpetic medications have found no associations for birth defects overall but have not examined the risk of specific birth defects. METHODS: The National Birth Defects Prevention Study ascertains population-based cases with birth defects and live-born controls without birth defects in 10 states across the United States for the purpose of identifying potential teratogenic risk factors. Mothers of cases and controls are interviewed within 2 years of their estimated date of delivery about demographic, medical and behavioural factors before and during pregnancy. This analysis examined the possible association between use of antiherpetic medications (acyclovir, valacyclovir or famciclovir) during early pregnancy and gastroschisis, a birth defect of the abdominal wall. RESULTS: The mothers of 1.1% (n = 10) of 941 gastroschisis cases and 0.3% (n = 27) of 8339 controls reported antiherpetic medication use during the month before conception through the third month of pregnancy. The adjusted odds ratios for such use in relation to gastroschisis were 4.7 [95% confidence interval 1.7, 13.3] and 4.7 [95% CI 1.2, 19.0] among women with and without self-reported genital herpes, respectively, when compared with women without antiherpetic use or herpes. Among women reporting no antiherpetic medication use, the odds ratio for self-reported genital herpes in relation to gastroschisis was 3.0 [95% CI 1.6, 5.7]. CONCLUSIONS: Our study raises the possibility of an increased risk of gastroschisis because of either antiherpetic medication use during early pregnancy or the underlying genital herpes infection for which it was indicated.

Antivirals for management of herpes zoster including ophthalmicus: a systematic review of high-quality randomized controlled trials.

BACKGROUND: There is lack of consensus from randomized controlled trials on the efficacy of antivirals in the management of herpes zoster. Therefore, a systematic review and meta-analysis was undertaken to provide better understanding of effectiveness of antivirals in management of herpes zoster. METHODS: A total of 12 randomized controlled trials with 7,277 patients were included in the review. Trials compared one antiviral to another (aciclovir, valaciclovir, famciclovir or brivudin) for a minimum of 7 days in immunocompetent patients presenting with herpes zoster diagnosed within 72 h of symptom onset. Primary outcome was reduction in pain. RESULTS: Compared with aciclovir, valaciclovir showed significant reduction in herpes-zoster-associated pain up to 112 days. The largest risk reduction in pain (36%) was seen at 21-30 days (relative risk [RR] 0.64, 95% CI 0.59, 0.70) with number needed to treat to benefit (NNT) of 3 (95% CI 2.7, 3.8). Famciclovir was also superior to aciclovir with a 46% reduction in risk of pain at 28-30 days (RR 0.54, 95% CI 0.48, 0.68) with NNT of 3 (95% CI 2, 5). Time to lesion healing and adverse effect profile was comparable. CONCLUSIONS: Evidence from quality trials have shown significant reduction in risk of pain with valaciclovir and famciclovir for management of herpes zoster including ophthalmicus. Valaciclovir or famciclovir should be preferred treatment options in patients with herpes zoster as they both provide significant reduction in risk of herpes-zoster-associated pain. Furthermore, the superior pharmacokinetics and more convenient dosing regimens with the use of valaciclovir and famciclovir clearly make them the preferred treatment option.

Safety and pharmacokinetics of a single 1500-mg dose of famciclovir in adolescents with recurrent herpes labialis.

An open-label study evaluated the safety (n = 53) and pharmacokinetics (n = 8) of single-dose therapy with 1500 mg famciclovir (prodrug of penciclovir) for recurrent herpes labialis in adolescents. Mean Cmax, mean AUC0-∞, and clearance for penciclovir were 9.37 µg/mL, 31.8 µg · h/mL, and 38.2 L/h, respectively, and within the range extrapolated from data in adults. Adverse events were generally mild and transient.

Use of acyclovir, valacyclovir, and famciclovir in the first trimester of pregnancy and the risk of birth defects.

CONTEXT: Herpes simplex and herpes zoster infections are common and often treated with antiviral drugs including acyclovir, valacyclovir, and famciclovir. Safety of these antivirals when used in the first trimester of pregnancy is insufficiently documented. OBJECTIVE: To investigate associations between exposure to acyclovir, valacyclovir, and famciclovir in the first trimester of pregnancy and risk of major birth defects. DESIGN, SETTING, AND PARTICIPANTS: Population-based historical cohort study of 837,795 live-born infants in Denmark from January 1, 1996, to September 30, 2008. Participants had no diagnoses of chromosomal aberrations, genetic syndromes, birth defect syndromes with known causes, or congenital viral infections. Nationwide registries were used to ascertain individual-level information on dispensed antiviral drugs, birth defect diagnoses (categorized according to a standardized classification scheme), and potential confounders. MAIN OUTCOME MEASURE: Prevalence odds ratios (PORs) of any major birth defect diagnosed within the first year of life by exposure to antiviral drugs. RESULTS: Among 1804 pregnancies exposed to acyclovir, valacyclovir, or famciclovir in the first trimester, 40 infants (2.2%) were diagnosed with a major birth defect compared with 19,920 (2.4%) among the unexposed (adjusted POR, 0.89; 95% confidence interval [CI], 0.65-1.22). For individual antivirals, a major birth defect was diagnosed in 32 of 1561 infants (2.0%) with first-trimester exposure to acyclovir (adjusted POR, 0.82; 95% CI, 0.57-1.17) and in 7 of 229 infants (3.1%) with first-trimester exposure to valacyclovir (adjusted POR, 1.21; 95% CI, 0.56-2.62). Famciclovir exposure was uncommon (n = 26), with 1 infant (3.8%) diagnosed with a birth defect. Exploratory analyses revealed no associations between antiviral drug exposure and 13 different subgroups of birth defects, but the number of exposed cases in each subgroup was small. CONCLUSION: In this large nationwide cohort, exposure to acyclovir or valacyclovir in the first trimester of pregnancy was not associated with an increased risk of major birth defects.

Famciclovir: a focus on efficacy and safety.

IMPORTANCE OF THE FIELD: Famciclovir is the prodrug of penciclovir, a guanosine analogue that inhibits viruses of the alpha sub-family of the Herpesviridae, as well as hepatitis B virus. It is indicated for management of mucocutaneous herpes simplex virus disease and acute herpes zoster, and has been investigated for management of hepatitis B virus infection. AREAS COVERED IN THIS REVIEW: Data for this review were identified by searches of papers published in English on Medline and Scopus, spanning the years 1975 through 1 February 2010 with the key words: 'famciclovir', 'famvir', 'penciclovir', 'herpes', 'oral', 'genital', 'varicella', 'zoster' and 'virus' in association with 'safety', 'toxicity', 'tolerability', 'efficacy' and 'indications'. Relevant references were also obtained from articles acquired through the search strategy. WHAT THE READER WILL GAIN: Readers are also provided with up-to-date information on the use of famciclovir for infections due to herpes simplex, varicella zoster and hepatitis B viruses. Clinical data pertaining to the safety and tolerability of famciclovir are also reviewed. TAKE HOME MESSAGE: Famciclovir is a safe, convenient, and well-tolerated drug when used for its approved indications. The most common side effects indicated in the majority of studies were headache and nausea. Data for its use in childhood and pregnancy are limited.

Single-dose pharmacokinetics of famciclovir in infants and population pharmacokinetic analysis in infants and children.

A multicenter, open-label study evaluated the single-dose pharmacokinetics and safety of a pediatric oral famciclovir (prodrug of penciclovir) formulation in infants aged 1 to 12 months with suspicion or evidence of herpes simplex virus infection. Individualized single doses of famciclovir based on the infant's body weight ranged from 25 to 175 mg. Eighteen infants were enrolled (1 to <3 months old [n = 8], 3 to <6 months old [n = 5], and 6 to 12 months old [n = 5]). Seventeen infants were included in the pharmacokinetic analysis; one infant experienced immediate emesis and was excluded. Mean C(max) and AUC(0-6) values of penciclovir in infants <6 months of age were approximately 3- to 4-fold lower than those in the 6- to 12-month age group. Specifically, mean AUC(0-6) was 2.2 microg h/ml in infants aged 1 to <3 months, 3.2 microg h/ml in infants aged 3 to <6 months, and 8.8 microg h/ml in infants aged 6 to 12 months. These data suggested that the dose administered to infants <6 months was less than optimal. Eight (44.4%) infants experienced at least one adverse event with gastrointestinal events reported most commonly. An updated pharmacokinetic analysis was conducted, which incorporated the data in infants from the present study and previously published data on children 1 to 12 years of age. An eight-step dosing regimen was derived that targeted exposure in infants and children 6 months to 12 years of age to match the penciclovir AUC seen in adults after a 500-mg dose of famciclovir.

One-day famciclovir vs. placebo in patient-initiated episodic treatment of recurrent genital herpes in immunocompetent Black patients.

BACKGROUND: There are no known racial differences in genital herpes disease pathogenesis or response to therapy. Despite high herpes simplex virus (HSV) seroprevalence in Black persons, clinical trials investigating the treatment of recurrent genital herpes (RGH) have typically enrolled a small proportion of Black patients. METHODS: This multicenter, double-blind, placebo-controlled study evaluated the efficacy and safety of patient-initiated, 1-day famciclovir 1000 mg twice-daily in immunocompetent Black adults (USA and South Africa) with RGH. Eligible patients were randomized (2:1) to famciclovir or placebo. The primary endpoint was time to healing of non-aborted genital herpes lesions (i.e., lesions that progressed beyond papule stage). Secondary endpoints included proportion of patients with aborted genital herpes lesions, time to resolution of associated symptoms, and safety. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov ; trial identifier NCT00477334. RESULTS: A total of 299 patients with RGH (66% female, median age = 37 years) received either 1-day famciclovir 1000 mg twice-daily (n = 201) or placebo (n = 98). In the modified intent-to-treat population, the estimated median time to healing of non-aborted genital herpes lesions was 5.38 days for famciclovir and 4.79 days for placebo (median of treatment differences = 0.26 days; 95% CI [-0.40, 0.98]; p = 0.416). Consistent findings were reported in the completer and per-protocol populations. No significant differences were reported for all secondary analyses. Adverse events (AEs) were consistent with the established safety profile of famciclovir: 18 (6%) patients had drug-related AEs (16 [8%] famciclovir; 2 [2%] placebo), none of which were serious or led to discontinuation or dose adjustment/interruption. There are some limitations of this research: many study sites either lacked prior experience in conducting clinical studies in patients with HSV infection or enrolled small numbers of patients, which may have compromised efficacy outcomes. Also, HIV antibody testing was not mandated at enrollment. CONCLUSION: This study showed similar efficacy and tolerability of 1-day treatment with famciclovir 1000 mg twice-daily compared to placebo in immunocompetent Black adults with RGH. Famciclovir has proven efficacy and safety in the overall RGH population. Further understanding of the efficacy of antiherpes therapy in Black patients with recurrent genital herpes may be warranted.

Pharmacokinetics and safety of famciclovir in children with herpes simplex or varicella-zoster virus infection.

Two multicenter, open-label, single-arm, two-phase studies evaluated single-dose pharmacokinetics and single- and multiple-dose safety of a pediatric oral famciclovir formulation (prodrug of penciclovir) in children aged 1 to 12 years with suspicion or evidence of herpes simplex virus (HSV) or varicella-zoster virus (VZV) infection. Pooled pharmacokinetic data were generated after single doses in 51 participants (approximately 12.5 mg/kg of body weight [BW] for children weighing < 40 kg and 500 mg for children weighing > or = 40 kg). The average systemic exposure to penciclovir was similar (6- to 12-year-olds) or slightly lower (1- to < 6-year-olds) than that in adults receiving a 500-mg dose of famciclovir (historical data). The apparent clearance of penciclovir increased with BW in a nonlinear manner, proportional to BW(0.696). An eight-step weight-based dosing regimen was developed to optimize exposure in smaller children and was used in the 7-day multiple-dose safety phases of both studies, which enrolled 100 patients with confirmed/suspected viral infections. Twenty-six of 47 (55.3%) HSV-infected patients who received famciclovir twice a day and 24 of 53 (45.3%) VZV-infected patients who received famciclovir three times a day experienced at least one adverse event. Most adverse events were gastrointestinal in nature. Exploratory analysis following 7-day famciclovir dosing regimen showed resolution of symptoms in most children with active HSV (19/21 [90.5%]) or VZV disease (49/53 [92.5%]). Famciclovir formulation (sprinkle capsules in OraSweet) was acceptable to participants/caregivers. In summary, we present a weight-adjusted dosing schedule for children that achieves systemic exposures similar to those for adults given the 500-mg dose.

Single-day, patient-initiated famciclovir therapy versus 3-day valacyclovir regimen for recurrent genital herpes: a randomized, double-blind, comparative trial.

BACKGROUND: Recurrent genital herpes is a major problem for patients worldwide. Early episodic treatment with short-course therapy is effective, often stopping progression of outbreaks. This study is the first head-to-head comparison of single-day famciclovir (1000 mg administered twice daily) versus 3-day valacyclovir (500 mg administered twice daily) for episodic therapy in immunocompetent patients. METHODS: In this multicenter, multinational, double-blind, parallel-group study, 1179 adults with a history of recurrent genital herpes were randomized 1:1 to receive either famciclovir or valacyclovir. Patients initiated treatment within 6 h after a recurrence. The primary objective was to establish noninferiority of single-day famciclovir, compared with a 3-day course of valacyclovir, in time to healing of all nonaborted lesions in a modified intent-to-treat population. RESULTS: This study established that single-day famciclovir therapy was noninferior to 3-day valacyclovir therapy in reducing time to healing of all nonaborted genital herpes lesions (median time to healing, 4.25 days vs. 4.08 days). Approximately one-third of patients in each treatment group had aborted genital herpes episodes, suggesting that both treatments have similar efficacy in preventing outbreaks or progression of lesions beyond the papule stage. There was no significant difference in time to resolution of symptoms associated with recurrence. The overall incidence of adverse events was similar (23.2% for the famciclovir group vs. 22.3% for the valacyclovir group), with headache, nausea, diarrhea, vomiting, and abdominal pain reported most often. CONCLUSIONS: Single-day famciclovir (1000 mg administered twice daily) was similar to 3-day valacyclovir (500 mg administered twice daily) in both efficacy and safety, representing a more convenient treatment for immunocompetent adults with recurrent genital herpes.

Famciclovir treatment options for patients with frequent outbreaks of recurrent genital herpes: the RELIEF trial.

BACKGROUND: Recurrent genital HSV outbreaks are common among those suffering from the disease. Antiviral medications taken as suppressive therapy can reduce the frequency of these recurrences and reduce viral shedding occurring in between recurrences. OBJECTIVES: To investigate the efficacy and safety of oral famciclovir as episodic (125 mg twice daily for 5 days) and suppressive (250 mg twice daily) treatment of recurrent genital herpes (RGH). STUDY DESIGN: This was a randomized, multicenter, 6-month, open-label study. Efficacy variables were time to first recurrence of RGH symptoms, and change in total score of the Recurrent Genital Herpes Quality of Life (RGHQoL) questionnaire. Subject satisfaction questions were summarized. RESULTS: 384 subjects were randomized. There was a highly statistically significant difference between treatments in time to first recurrence of symptoms in favor of suppressive treatment (p<0.0001). There was no significant difference between treatments in total score of the RGHQoL or in subject satisfaction with treatment. CONCLUSIONS: This study demonstrated that, compared to episodic treatment, suppressive treatment with oral famciclovir may extend the time to symptomatic outbreaks in patients with frequent recurrences of genital herpes.

Famciclovir-induced leukocytoclastic vasculitis.

OBJECTIVE: To report a case of famciclovir-induced leukocytoclastic vasculitis (LCV). CASE SUMMARY: A 67-year-old white female presented to the hospital for evaluation of large, bilateral palpable purpura; coalescing ulcers with central eschars; and small, red violaceous papules on her legs and groin. Approximately 2 months prior to this hospitalization, the woman was diagnosed with shingles of her left T1-T2 nerve distribution and was treated with famciclovir 500 mg 3 times daily, which was her first exposure to this medication. Her shingles resolved; however, on day 4 of treatment, she began to notice red spots on both of her legs that began to progressively blister and increase in size. She discontinued famciclovir at that time. The rash persisted and spread to her abdomen, groin, legs, feet, and toes. She underwent punch biopsy that revealed LCV. Workup was negative for antinuclear antibody, rheumatoid factor, hepatitis B and C virus, perinuclear-staining antineutrophil cytoplasmic antibodies, cytoplasmic-staining antineutrophil cytoplasmic antibodies, antibodies to extractable nuclear antigens, proteinase 3, and myeloperoxidase. The patient improved with daily oral steroids and local wound care. DISCUSSION: LCV has been reported only once before in the English literature as of January 2008. The most common cause of LCV is medication use, but it is a diagnosis of exclusion. It is hypothesized that drugs act as haptens, which cause an immune response. An objective causality assessment using the Naranjo probability scale suggested that famciclovir was the probable cause of LCV in this patient. CONCLUSIONS: Healthcare professionals should be aware of the possible development of famciclovir-induced LCV.

Famciclovir: a review of its use in herpes zoster and genital and orolabial herpes.

Famciclovir (Famvir) is the oral prodrug of penciclovir, an agent that has demonstrated antiviral activity against herpes simplex viruses, type 1 (HSV-1) and 2 (HSV-2) [which cause orolabial and/or genital herpes simplex], and against varicella zoster virus (VZV) [a reactivation of which leads to herpes zoster]. Famciclovir has efficacy similar to that of aciclovir (in immunocompetent or immunocompromised patients) or valaciclovir (in immunocompetent patients) in the treatment of herpes zoster, and efficacy similar to aciclovir in the treatment of first or recurrent episodes of genital herpes (in immunocompetent or immunocompromised patients). Famciclovir also has efficacy in the suppression of recurrent episodes of genital herpes, and in the treatment of orolabial herpes, in immunocompetent patients. As such, famciclovir is a well tolerated first-line option for the treatment of herpes zoster and the treatment and suppression of genital herpes, and is approved for the treatment of recurrent orolabial herpes. Convenient patient-initiated single-day (for recurrent genital herpes) and single-dose (for orolabial herpes) dosage regimens may contribute to treatment compliance, patient acceptability and subsequent treatment outcomes.

Improved outcome of chronic hepatitis B after heart transplantation by long-term antiviral therapy.

Chronic hepatitis B progresses to cirrhosis in the majority of immunosuppressed patients. The outcome of long-term antiviral therapy in HBV-infected organ transplant recipients is unknown. In 1996, we included 20 heart transplant (HT) recipients in a pilot trial to treat chronic hepatitis B with famciclovir. At that time, bridging fibrosis or cirrhosis was evident in 15 individuals (75%). From 1998 onwards, patients were switched to lamivudine in case of primary or secondary virological nonresponse to famciclovir. Adefovir or tenofovir became available at our centre for HT recipients in 2002. After 103 months, one patient was still on famciclovir showing a complete virological response. Sixteen patients were switched to lamivudine after 0.5-4 years of famciclovir therapy. Six of those showed a long-term response to lamivudine therapy lasting for up to 7 years. Lamivudine resistance developed in the remaining 10 patients (63%), in 4 of them successful rescue therapy (adefovir n = 3, tenofovir n = 1) could be initiated. Only one hepatocellular carcinoma developed, which was successfully treated by locoregional ablative therapy. Nine patients died (45%), with lamivudine-resistance-related liver failure as the cause of death in five cases. Significant improvement of Ishak fibrosis scores could be demonstrated in six of the seven patients with more than two sequential liver biopsies available. Long-term antiviral therapy of chronic hepatitis B can lead to regression of liver cirrhosis in patients after organ transplantation, unless viral resistance occurs. This study demonstrates the urgent need for further antivirals to overcome antiviral resistance.

Comparative efficacy of famciclovir and valacyclovir for suppression of recurrent genital herpes and viral shedding.

BACKGROUND: Daily antiviral therapy with famciclovir and valacyclovir has been shown to be effective in reducing both symptomatic and asymptomatic reactivation of herpes simplex virus type 2 (HSV-2) when compared to placebo. However, few comparative studies between the 2 antivirals have been performed. OBJECTIVES: To compare the clinical and virologic effects of famciclovir and valacyclovir administered as daily suppressive therapy for persons with genital herpes. STUDY DESIGN: Two randomized, double-blind, placebo-controlled studies comparing daily famciclovir 250 mg bid with valacyclovir 500 mg qd were performed. Study 1 randomized 320 participants and compared the clinical effect of the drugs given for 16 weeks, and study 2 enrolled 70 HSV-2 seropositive subjects and compared the virologic effect of the drugs given for 10 weeks. RESULTS: In study 1, the time to first recurrence was similar in famciclovir and valacyclovir recipients, hazard ratio (HR) 1.17 (95% CI, 0.78-1.76), but time to first virologically confirmed recurrence was shorter among famciclovir recipients, HR = 2.15 (95% CI, 1.00-4.60). In study 2, HSV was detected on 3.2% of days among famciclovir recipients and 1.3% of days among valacyclovir recipients, relative risk 2.33 (95% CI, 1.18-4.89). CONCLUSION: Valacyclovir appear to be somewhat better than famciclovir for suppression of genital herpes and associated shedding. Further comparative trials of antiviral drugs for various indications should be performed as acyclovir and penciclovir appear to have different ability to abrogate HSV reactivation.

Clinic-initiated, twice-daily oral famciclovir for treatment of recurrent genital herpes: a randomized, double-blind, controlled trial.

BACKGROUND: Famciclovir, the oral prodrug of penciclovir, is effective for the treatment of recurrent genital herpes. This randomized, clinic-initiated, double-blind trial compared the therapeutic efficacy and safety of treatment with famciclovir at dosages of 125 mg, 250 mg, and 500 mg twice daily for 5 days with placebo in immunocompetent adults with a recurrent episode of genital herpes. METHODS: Efficacy and tolerability were assessed in 308 patients with lesions present for no more than 6.5 h at the time of the first dose. Two assessments per day were performed to increase the precision of the determination of study end points. RESULTS: All doses of famciclovir were significantly more effective than placebo in reducing the time to cessation of viral shedding, complete lesion healing, and loss of all lesion-associated symptoms, particularly lesion tenderness, pain, and itching. Patients receiving treatment with famciclovir were significantly less likely to experience new lesions than were patients receiving placebo. All doses of famciclovir were tolerated as well as placebo was. There was no difference in efficacy or tolerability among the different doses of famciclovir; the lowest effective dose was 125 mg twice per day. CONCLUSIONS: In immunocompetent adults with recurrent genital herpes, a 5-day course of famciclovir at a dosage of 125 mg, 250 mg, or 500 mg twice per day was significantly more effective than was placebo in reducing the duration of viral shedding and symptoms and in accelerating lesion healing. These results support the use of treatment with famciclovir at a dosage of 125 mg for 5 days as an effective, well-tolerated treatment for episodes of recurrent genital herpes.

[Clinical investigation of famciclovir in chronic hepatitis B patients irresponsive to alpha interferon treatment].

OBJECTIVES: To evaluate the efficacy and safety of famciclovir on the decreasing levels of serum HBV-DNA and ALT and HBeAg/antiHBe seroconversion in chronic hepatitis B patients irresponsive to 3 months treatment with alpha interferon. METHODS: Two hundred and nineteen patients with chronic HBV infection, defined as positive HBsAg, HBeAg and HBV DNA, were enrolled and randomly half-and- half put into famciclovir and placebo groups. The two groups received either famciclovir 500 mg tid or a placebo treatment for 24 weeks, and then were followed-up for another 24 weeks with no treatment. RESULTS: At the end of 24 weeks, the log value of HBV DNA dropped from 6.54+/-1.26 to 5.70+/-2.03 in the famciclovirt group and were elevated from 6.30+/-1.32 to 6.51+/-1.65 in the placebo group (P < 0.01). The rate of cases with persistence HBV DNA dropped 2 log of quantity in the famciclovir group and was 28.28% (28/99); it was 9.47% (9/95) in the placebo group (P < 0.01). Those with persistence negative HBV DNA was 28.28% (28/99) in the flamciclovir treated group and 14.74% (14/95) in the placebo group (P < 0.05). Those persistently being HBeAg negative were 7.69% (7/91) in the famciclovir treated group and 3.33% (3/90) in the placebo group (P > 0.05). The HBeAg/antiHBe seroconversion was 4.40% (4/91) in the famciclovir group and 2.22% (2/90) in the placebo group (P > 0.05). The percentage of cases with normal of ALT level was 15.15% in the famciclovir group and 6.35% in the placebo group (P < 0.05). CONCLUSION: Famciclovir is effective in inhibiting HBV DNA replication and in decreasing serum ALT levels. The rate of HBeAg/antiHBe seroconversion in the famciclovir treated group was similar to that of the placebo group. Famciclovir was well tolerated without severe adverse effects during our treatment.