Famciclovir Capsules

This product is rapidly converted into the antiviral compound penciclovir in the body, which has an inhibitory effect on herpes simplex virus type Ⅰ (HSV-1), herpes simplex virus type Ⅱ (HSV-2) and varicella zoster virus (VZV). In cell culture studies, the inhibitory effect of penciclovir on the following viruses is ranked in the order of 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 into monophosphate penciclovir, which is then converted into triphosphate penciclovir by cellular kinase. In vitro studies have shown that triphosphate penciclovir inhibits the activity of HSV-2 polymerase by competing with guanosine triphosphate, thereby selectively inhibiting the synthesis and replication of herpes virus DNA. A 2-year carcinogenicity experiment in rats and mice confirmed that the incidence of breast cancer increased in female rats receiving 600 mg/kg/day (equivalent to the recommended human dose of 500 mg, or 125 mg, 1.5 to 9 times twice a day). Testicular toxicity was found in male rats, mice and dogs after taking this product. No reproductive toxicity was found in female rats taking this product at a dose of 1000 mg/kg/day.

The main ingredient of this product is famciclovir. Chemical name: 2-[2-(2-amino-9H-purine-9-yl)ethyl]-1,3-propanediol-diethyl ester. Molecular formula: C14H19N5O4 Molecular weight: 321.34

This product is in the form of capsules.

Suitable for herpes zoster and primary genital herpes.

Oral administration, 0.25g for adults once, 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 adjust the dose according to their renal function. The recommended doses are as follows: creatinine clearance dose ≥60ml/min, 0.25g for adults once, 40-59ml/min, 0.25g for adults once every 8 hours, 20-39ml/min, 0.25g for adults once every 12 hours, <20ml/min, 0.125g for adults once every 24 hours, once every 48 hours.

Common adverse reactions are headache and nausea. In addition, the following reactions may be seen: 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, itchy skin, sinusitis, pharyngitis, etc.

Patients who are allergic to this product or penciclovir are contraindicated.

Precautions for children: The safety and effectiveness of this product for patients under 18 years of age have not been determined. Precautions for pregnancy and lactation: No abnormalities were observed in the development of the fetuses of pregnant rats and rabbits after taking this product, but there is a lack of human clinical data. Pregnant women should fully weigh the pros and cons of using this product. Rat experiments have confirmed that the concentration of penciclovir, the precursor of this product, in breast milk is higher than the plasma concentration, but whether it is secreted through human milk is still inconclusive. Lactating women should stop breastfeeding when using this product. Precautions for the elderly: The types and incidence of adverse reactions after taking this product in the elderly over 65 years old are similar to those in young people, but renal function should be monitored before taking the medicine and the dosage should be adjusted in time.

1. When this product is used in combination with probenecid or other drugs that are actively excreted by the renal tubules, it may lead to an increase in the concentration of penciclovir in plasma. 2. It may interact with other drugs that are metabolized by aldehyde oxidase.

Keep away from light and store in sealed container.

0.125g

24 months