Product Overview
【Drug Name】
Generic Name: Famciclovir Capsules
Brand Name: Xianlinna
English Name: Famciclovir Capsules
Pinyin: Fanxiluowei Jiaonang
【Ingredients】
The main ingredient of this product is famciclovir. Chemical name: 2-[2-(2-amino-9H-purin-9-yl)ethyl]-1,3-propanediol-diethyl ester. Molecular formula: C14H19N5O4 Molecular weight: 321.34
【Appearance】
This product is a capsule.
【Indications】
Suitable for herpes zoster and primary genital herpes.
【Dosage and Administration】
Oral administration. Adults take 0.25g once every 8 hours. The course of treatment for herpes zoster is 7 days, and the course of treatment for primary genital herpes is 5 days. Patients with renal insufficiency should have their dosage adjusted according to their renal function. Recommended dosages are as follows: Creatinine clearance ≥60 ml/min: Adults 0.25g once, every 8 hours; 40–59 ml/min: Adults 0.25g once, every 12 hours; 20–39 ml/min: Adults 0.25g once, every 24 hours; <20 ml/min: Adults 0.125g once, every 48 hours.
【Adverse Reactions】
Common adverse reactions are headache and nausea. Other possible adverse reactions include:
1. Nervous system: dizziness, insomnia, drowsiness, paresthesia, etc.
2. Digestive system: diarrhea, abdominal pain, indigestion, anorexia, vomiting, constipation, flatulence, etc.
3. Systemic reactions: fatigue, pain, fever, chills, etc.
4. Other reactions: rash, pruritus, sinusitis, pharyngitis, etc.
【Contraindications】
This product is contraindicated in patients with known hypersensitivity to penciclovir or other similar products.
【Precautions】
1. The efficacy of this product in preventing recurrence of genital herpes, ocular herpes zoster, disseminated herpes zoster, and herpes in immunocompromised patients has not been confirmed.
2. In patients with renal insufficiency, the apparent plasma clearance, renal clearance, and plasma clearance rate constant of penciclovir decrease with decreasing renal function; therefore, dosage and administration should be adjusted accordingly.
3. No dosage adjustment is required for patients with compensated liver function. Pharmacokinetic studies have not been conducted in patients with decompensated liver function.
4. Food has no significant effect on bioavailability. Oral administration of 0.5g of this product three times a day for 7 consecutive days did not show any accumulation of penciclovir.
5. Deterioration of viral thymidine deoxynucleoside kinase or DNA polymerase can lead to the development of penciclovir-resistant mutant strains of HSV or VZV. If a patient's clinical treatment is ineffective, viral resistance to penciclovir should be considered. Mutant strains resistant to acyclovir are also resistant to penciclovir.
6. Patients must be informed that this product cannot cure genital herpes. Whether this product can prevent the spread of the disease is unclear, but genital herpes can be transmitted through sexual contact; therefore, sexual contact should be avoided during treatment.
【Special Populations】
Precautions for Children: The safety and efficacy of this product in patients under 18 years of age have not been established.
Precautions for Pregnancy and Lactation: No abnormalities were observed in fetal development after administration of this product to pregnant rats and rabbits, but human clinical data are lacking. Pregnant women should carefully weigh the benefits and risks before using this product. Rat experiments have shown that the concentration of the prodrug penciclovir in breast milk is higher than that in plasma, but whether it is excreted in human milk is inconclusive. Lactating women should discontinue breastfeeding before using this product.
Precautions for the Elderly: The types and incidence of adverse reactions in patients over 65 years of age are similar to those in younger patients, but renal function should be monitored before administration and the dosage adjusted promptly.
【Drug Interactions】
1. Concomitant use of this product with probenecid or other drugs actively excreted by the renal tubules may lead to an increase in plasma penciclovir concentration.
2. It may interact with other drugs metabolized by aldehyde oxidases.
【Pharmacological Action】
This product is rapidly converted in vivo into penciclovir, a compound with antiviral activity, which inhibits herpes simplex virus type I (HSV-1), herpes simplex virus type II (HSV-2), and varicella-zoster virus (VZV). In cell culture studies, the order of inhibitory activity of penciclovir against these viruses is HSV-1, HSV-2, and VZV. The mechanism of action is as follows: In cells infected with the above viruses, viral thymidine kinase phosphorylates penciclovir to penciclovir monophosphate, which is then converted to penciclovir triphosphate by cellular kinases. In vitro studies show that penciclovir triphosphate selectively inhibits the synthesis and replication of herpesvirus DNA by competitively inhibiting the activity of HSV-2 polymerase, in contrast to guanosine triphosphate. Two-year carcinogenicity studies in rats and mice confirmed that female rats receiving 600 mg/kg/day (equivalent to 1.5 to 9 times the human recommended dose of 500 mg, or 125 mg twice daily) had an increased incidence of breast cancer. Testicular toxicity was observed in male rats, mice, and dogs after administration of this product. No reproductive toxicity was observed in female rats administered 1000 mg/kg/day.
【Storage】
Protected from light, sealed.
【Specifications】
0.125g
【Packaging Specifications】
0.125g * 6 capsules
【Shelf Life】
24 months
【Approval Number】
National Drug Approval Number H19991099
【Manufacturer】
Company Name: Dalian Meiluo Pharmaceutical Factory
