famciclovir
Regulatory sources consulted
Approved indications
- Herpes zoster, ophthalmic zoster, and genital herpes in adults according to immune status and episode.
Contraindications
Absolute
- Hypersensitivity to famciclovir or penciclovir.
Clinical warnings
- It may cause acute renal failure if not adjusted for renal function; assess clearance before treatment. — CIMA/AEMPS, ficha técnica 71960
Drug interactions
- ModerateProbenecid
Mechanism: It may increase penciclovir exposure.
Recommendation: Monitor toxicity, especially in renal impairment.
CIMA/AEMPS, ficha técnica 71960
Adverse events
Common (≥1%)
Headache and nausea
Rare but serious
Acute renal failure, confusion, hallucinations, and severe skin reactions
Pregnancy and lactation
Use during pregnancy only if benefit outweighs risk. Decide whether to discontinue breastfeeding or treatment.
Recent literature (PubMed)
Herpes simplex virus (HSV) and varicella zoster virus (VZV) are alpha herpesviruses that establish life-long latent infection in neuronal ganglia after primary infection. Periodic reactivation of these viruses results in recurrent infections that can have significant impact on patients' quality of life. HSV commonly causes oral and genital mucocutaneous infections whereas VZV is responsible for varicella/chickenpox and herpes zoster/shingles, but cancer patients are at particularly higher risk of complications including disseminated and visceral infections due to impaired cell-mediated immunity. While diagnosis of more common HSV and/or VZV infections is frequently clinically based, immunocompromised hosts may have atypical skin presentation or visceral involvement. Thus, diagnostic confirmation using virus-specific tests such as polymerase chain reaction or immunohistochemical staining is crucial in some cases. Oral acyclovir, valacyclovir and famciclovir are usually used for mild to moderate infections and intravenous acyclovir is the drug of choice for severe or disseminated infections. Foscarnet can be used when acyclovir-resistance is confirmed or suspected. Pharmaceutical prophylaxis against HSV and/or VZV should be considered in high-risk cancers patients. Currently, there is no commercially available vaccine against HSV, but VZV vaccines are available to prevent varicella and zoster. Because there is no published experience with famciclovir during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.[1]
The most refractory symptom of herpes zoster (HZ) is pain. Approximately 90% of people who have HZ suffer from pain. Early use of antiviral medications has been found to reduce pain across all stages of the disease. Although many antiviral agents via oral or intravenous administration were recommended by clinical practice, the best approach to prevent HZ-associated pain remains uncertain. The purpose of this study was to compare the efficacy and adverse events of various antiviral agents used for the treatment of HZ-associated pain through a network meta-analysis. A systematic review and meta-analysis. The Cochrane Register of Controlled Trials, Embase, and PubMed were searched from inception to Feb 2020. Randomized clinical trials evaluating antiviral agents currently available for treating HZ-associated pain were included. We extracted data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and conducted network meta-analyses with random-effects models. The primary outcome was the presence of acute pain at the end of anti-virus treatment, and the secondary outcomes included the presence of pain at 28-30 days after the onset of the acute herpetic rash, the presence of postherpetic neuralgia (PHN), and any other adverse events. A total of 17 randomized control trials with 5,579 participants were included in this study. According to the results of the network meta-analysis, for the treatment of acute pain, there was no significant difference between oral acyclovir and intravenous acyclovir. Furthermore, oral famciclovir was the most effective treatment concerning both the odds ratio (OR) (superior to placebo OR = 0.25; 95% CI: 0.13~0.48) and the surface under the cumulative ranking curve (SUCRA) values of 0.84 for the treatment of acute pain among all the oral antiviral agents. For the presence of pain at 28-30 days, no significant difference was observed in efficacy between all antiviral treatments and place
Herpes Simplex Virus (HSV) infections, caused primarily by HSV-1 and HSV-2, are among the most prevalent viral diseases worldwide, with recurrent manifestations that significantly affect quality of life. Therapeutic strategies include both topical and systemic interventions, each with distinct goals. This systematic review was conducted according to PRISMA guidelines. A comprehensive search of PubMed, Scopus, and Web of Science (2005-2025) identified studies evaluating topical or systemic treatments for HSV. Eligible studies included randomized controlled trials and observational studies reporting validated clinical outcomes. Topical treatments, including acyclovir cream, docosanol, and newer formulations, primarily reduce lesion duration and alleviate local symptoms when applied early. These interventions have limited systemic absorption and generally do not influence recurrence frequency. Novel delivery methods and combination strategies, such as acyclovir-hydrocortisone formulations or photodynamic therapy, may enhance local efficacy and symptom control. Systemic Therapies: Systemic antivirals, such as acyclovir, valacyclovir, and famciclovir, target both lesion resolution and recurrence prevention. Evidence from randomized trials supports their use for episodic and suppressive therapy, including short-course, high-dose regimens that improve adherence while controlling symptoms. Systemic therapy is particularly indicated for recurrent, disseminated, or high-risk infections. Topical and systemic therapies serve complementary roles in HSV management. Topical agents are useful for localized or initial episodes, while systemic therapy addresses broader clinical objectives, including recurrence reduction. Future research should focus on mechanism-based therapies, novel delivery systems, and standardized outcome measures to guide personalized treatment strategies. Emerging therapies targeting viral latency, immune modulation, and gene-editing technologies hold promise
This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific therapeutics are described in alphabetical order including classic antiviral drugs, such as acyclovir, abacavir, adefovir, amantadine, didanosine, entecavir, ganciclovir, interferon, lamivudine, penciclovir, famciclovir, oseltamivir, ribavirin, and zidovudine, repurposed drugs, such as ivermectin and nitazoxanide, which were originally used as antiparasitic drugs, and some others substances showing antiviral activity, such as ampligen, azo derivates, docosanol, fluoroarabinosylpyrimidine nucleosides, and novel peptides. Most of them have only been used for research purposes and are not widely used in clinical practice because of a lack of essential pharmacokinetic and safety data. Suggested future research directions are also highlighted.