Product Overview
[Drug name]
Generic name: Metronidazole Vaginal Gel
Trade name: Nimeixin
English name: Metronidazole Vaginal Gel
Chinese Pinyin: Jiaxiaozuo Yindao Ningjiao
[Properties]
This product is a slightly yellow transparent gel.
[Indications]
For the treatment of bacterial vaginosis.
[Specifications]
5g:37.5mg
[Usage and Dosage]
For intravaginal use, once in the morning and evening each day, 5g each time (equivalent to 37.5mg of metronidazole), 5 to 7 days as a course of treatment.
The patient takes a recumbent position, removes the front cover of the applicator, inserts the front end of the applicator deep into the vagina, and pushes the booster rod to allow the gel to enter the deep vagina. Take out the applicator and discard it.
[Adverse Reactions]
Adverse reactions of this product are rare and mild, mainly including:
1. Genital tract: Candida cervicitis and vaginitis, vaginal, perineal or vulvar pruritus, frequent urination, vaginal or vulvar burning, discomfort, irritation (not caused by Candida) and vulvar swelling.
2. Long-term high-dose use can cause epileptic seizures and peripheral neuropathy after absorption through the mucosa, the latter of which is mainly manifested as numbness and paresthesia of the extremities. In some cases, long-term use may cause persistent peripheral neuropathy.
3. Other common adverse reactions include:
(1) Gastrointestinal reactions, such as nausea, loss of appetite, vomiting, diarrhea, abdominal discomfort, taste changes, dry mouth, metallic taste in the mouth, etc.
(2) Reversible neutropenia.
(3) Allergic reactions, rash, urticaria, itching, etc.
(4) Central nervous system symptoms, such as headache, dizziness, syncope, paresthesia, limb numbness, ataxia and mental confusion, etc.
(5) Other symptoms include fever, cystitis, dysuria, dark urine, etc., which are all reversible and recover spontaneously after discontinuation of the drug.
[Contraindications]
It is contraindicated for patients who are allergic to this product or azole drugs, as well as patients with active central nervous system diseases and blood diseases.
[Use in pregnant and lactating women]
There are currently no sufficiently well-controlled studies on the use of metronidazole vaginal gel in pregnant women. The existing public data are all from case-control studies, cohort studies, and two meta-analyses of more than 5,000 pregnant women who have used metronidazole during pregnancy. Several studies included metronidazole exposure in the first three months of pregnancy. One study showed that neonatal exposure to metronidazole before birth increased the risk of cleft lip and palate, but these findings have not been confirmed. In addition, more than 10 randomized placebo-controlled trials recruited more than 5,000 pregnant women to evaluate the incidence of premature birth and antibiotics (including metronidazole) for the treatment of bacterial vaginosis. Most studies did not show an increased risk of congenital anomalies or other adverse fetal outcomes with metronidazole exposure during pregnancy. The other three studies also did not show an increased risk of cancer in infants after metronidazole exposure during pregnancy. However, these studies have limited ability to detect risk signals. Metronidazole can cross the placental barrier, and its effect on human embryonic organ formation is still unclear. Reproductive toxicity studies have found that when rats, rabbits, and mice were given doses of metronidazole similar to the maximum recommended dose for humans, no adverse effects on the embryo were shown.
[Pharmacology and Toxicology]
Metronidazole has a strong antibacterial effect on most anaerobic bacteria, but has no effect on aerobic bacteria and facultative anaerobes. The antibacterial spectrum includes Bacteroides fragilis and other Bacteroides, Fusobacterium, Clostridium perfringens, Eubacterium, Veillonella, Peptococcus, and Peptostreptococcus. Its bactericidal concentration is slightly higher than the inhibitory concentration.
The bactericidal mechanism of metronidazole has not been fully elucidated, and the nitroreductase of anaerobic bacteria plays an important role in the energy metabolism of sensitive strains. The nitro group of this product is reduced to a cytotoxin, which acts on the DNA metabolism process of bacteria and promotes cell death.
【Pharmacokinetics】
According to literature reports, 12 healthy subjects took a single vaginal application of 5g of metronidazole gel (equivalent to 37.5mg of metronidazole). 6 to 12 hours after use, the average peak blood concentration (Cmax) of metronidazole was 237ng/ml (range 152-368ng/ml), which is equivalent to 2% of the average peak blood concentration (Cmax=12.785μg/ml, range 10.013-17.4μg/ml) of the same group of subjects 1 to 3 hours after taking a single oral dose of 0.5g of metronidazole. Its area under the curve (AUC) is about 4% of that of a single oral administration. After dose correction, the absorption degree of vaginal administration is about half of that of oral administration. Single and multiple doses of 5g of metronidazole gel were given to 4 patients with bacterial vaginosis, and their average peak blood concentration (Cmax) was 214ng/ml on the first day and 294ng/ml on the fifth day, ranging from 228 to 349ng/ml.
[Storage] Sealed, stored in a cool place (no more than 20°C).
[Packaging] Disposable cylindrical plastic applicator, plastic sealed, 1 piece/box.
[Validity period] 24 months
[Approval number] National Medicine Standard H20041426
